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A comparative study of certain species of gigartina with reference to their periodicity

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A comparative study of certain species of gigartina with reference to their periodicity

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Content A COMPARATIVE STUDY OP CERTAIN SPECIES OP
GIGARTINA WITH REFERENCE TO
THEIR PERIODICITY
ft*
/}$7*
A Thesis
Presented to
the Faculty of the Department of Botany
University of Southern California
In Partial Fulfillment
of the Requirements for the Degree
Master of Science
by
Josephine Hervey
February 1935
UMI Number: EP41393
All rights reserved
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Otesirtatfcm Pab ftssh io f
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This thesis, w ritten under the direction of the
candidate’s Faculty Committee and approved by
all its members, has been presented to and ac
cepted by the Council on Graduate Study and
Research in partial fulfillm ent of the require
ments fo r the degree of
. J & a , s f e a r . . q £ . . S . f t i sjciq ..
D ean
D ate ?®}?™ary*1935
3 ^ »
i
i ^ e
Faculty Committee
TABLE OP CONTENTS
CHAPTER PAGE
INTRODUCTION ............... .. .............» 1
I. HISTORICAL REVIEW............ ......... 3
A. Early work on Gigartina ........ 3
B. Late and Recent Work on Gigartina.......... 4
C« Periodicity in Algae ..... 7
D. Biological and Economic Significance....... 8
II . HABITAT RELATIONS ......... 9
A. Places of Collection .... 9
B. Geography and Rock Formation..... 11
C. Tides and Currents ......................... 13
D. Algae Collected ...... 14
III. COLLECTION AND .EXAMINATION OF SPECIMENS.... 16
A. Collecting Periods......................... 16
B. Method of Study ........... 17
C. General Observations ...... 21
IV. RESULTS OF SPECIAL OBSERVATIONS ON THE THREE
SPECIES OF GIGARTINA. .... 27
A. Gigartina Watonlana J, &g.................. 27
B. Gigartina Leptorynchos J. Ag...... 37 •
C• Gigartina Canaliculata Harvey .... 43
V. CERTAIN OTHER SPECIES OF THE GKNUS GIGARTINA 49
VI. DISCUSSION.................................... 57
VII. SUMMARY..................... 59
ii
CHAPTER PAGE
VIII. ACKNOWLEDGMENTS . . 61
IX, LITERATURE CITED....... . ............... 62
X. PLATES AND EXPLANATIONS ............... 65
LIST OP TABLES
TABLE PAGE
- * - • Gigartina Eatoniana showing Occurrence of
Reproductive Structures............... 30
II. Gigartina heptorynchos Showing Occurrence of
Reproductive Structures....................... 42
III. Gigartina Canaliculata Showing Occurrence of
Reproductive Structures ............ 45
LIST OF FIGURES
FIGURE' PAGE
1. Graph Showing Periodicity in - Gigartina
Eaton!ana*......................... 33
.2, Graph Showing Periodicity in Gigartina
.heptorynchos ............. 40
\i®. Graph Showing Periodicity in Gigartina
Ca.nalieu.lat a. ................. 47
LIST OP PLATES
PLATS PAGE
I. Type Plants of Gigartina Eaton!ana............ 66
II. Type Plants of Gigartina Leptorynchos.......... 68
III* Type Plants of Gigartina Canaliculata........ 70
IV. Cystocarpic Structures of Gigartina Baton!ana.. 72
V. Antheridial Structures of Gigartina Eatoniana.. 74
VI. Tetrasporic Structures of Gigartina Eatoniana.. 76
A COMPARATIVE STUDY OF CURTAIM SPECIES OF GIGARTINA
WITH REFERENCE TO THEIR PERIODICITY
INTRODUCTION
A survey of the available publications on the
genus Gigartina shows a predominance of species on the
southern California coast. Out of the seventy-five species
to be found throughout the world as listed in-the works of
J. G. Agardhp Setchell and Gardner^ have recheeked and
cataloged twenty-four species on the Pacific coast of
North America with nineteen of the latter in or extending
into the southern California area. Although the classi
fication of the genus is assuming an orderly arrangement,
nothing seems to be known concerning the time of occurrence
of the reproductive structures among the different species,
and very little has been published regarding the morphological
characteristics of these structures which is necessary for
a complete survey of their life cycles. The purpose of this
paper is to present the results of a study of the inter
related problems of morphology and periodicity among these
perennial red algae.
In general the systematic position of the Gigartinae
described as members of the family Gigartinaceae with
J. G. Agardh, Species, Genera Et Ordines Algarum,
(Lund. 1848-1876). -------- ---------------
P
W. . . A. Setchell, and N, L. Gardner, A Preliminary
Survey of Gigartina with Reference to Its No. AmeF7“SpecTes,
XunTvT oT Calif. Pub. " in Bot. Vol . T7., No’ . X01 T9'33~5E
hemispherical or spherical, protuberant cystocarps.
These species are further- segregated into series : First,
those with terete to cEomplarcsfctee fronds; lateral branches
numerous, pinnate to sub-pinnate; cystocarp, a spore mass
with a looser or denser, proper pericarp. Secondly, there
are the species with fronds longer or shorter, and
cylindrical stipes; slightly dichotomous or in turn
sparingly split, or proliferous from margins or surfaces,
cystocarps with a dense proper pericarp. And the third
series contains those plants with fronds complanate, at
least above, dichotomously or palmately branched, lateral
branches as irregular proliferations, marginal or super
ficial cystocarps protruding, sessile or pedicellate
cystocarpic spore mass lacking in proper pericarp. These
three series are divided into type species which further
differentiate the genus. The position of the individual
species of Gigartina in this classification will be further
discussed under special observations.
It is evident that the structure in the life cycle,
i. e. the cystocarp, is particularly important to the study
of variations within the genus Gigartina of the three major
species considered in this paper, namely Gigartina
eatoniana J. G. Agardh, Gigartina leptorynchos J. G. Agardh,
< .
and Gigartina canaliculate Harvey# The 'cystocarp; isc an
important point in differentiation, but on careful study
there are found two other structures of equal importance for
3
consideration in the periodicity of the plants. These
structures are antheridia and tetraspores.
HISTORICAL REVIEW
Early Work on Gigartina
The genus Gigartina was first proposed in algal
literature by Stackhouse in 1S09 according to Setchell and
Gardner.'*' The generic name was derived from the Greek
word meaning Grape Stones’ 1, The earliest references to
Gigartina are all of European origin. In 1813 Lamouroux
listed the genus although he included species of a
varying type. C. Agardh in 1820 listed species of the
genus under Sphaerococcus, but they were removed from this
classification in 1830 by Greville. In 1842, J. G. Agardh
gave the genus a more definite characterization limiting its
range and'making further revisions in 1899, This final
revision brought the number of species up to 69, Kuetzing
in his Phycologia Generalis In 1843 had previously denoted
several species. The first observations in relation to
pacific coast species were made from specimens collected
along this coast by English and Russian groups of explorers
from 1742 to 1899. Many of their specimens were fragmentary
and frequently not characteristic of the species.
1 W. A. Setchell, and N. L. Gardner, Marine Algae
of northwestern America (Univ. of Calif, Pub. m Bo't".
Voir. 037^----
Late and Recent Work on Gigartina 4
The recent publications and references on Gigartina
are found in herbarium and monograph form. The herbarium
of the University of California contains algae collected
as early as 1872 which give a splendid study of the
range of these plants along the Pacific coast, and com
parative structures of plants collected at that time with
the more extensive recent collectionss. The Los Angeles
Library has a small collection by Lawrence made in 1898
showing five carefully preserved and labeled species}
Lawrence having listed Gigartina spinosa, Gigartina
canaliculata and Gigartina horrida. Special investigations
of the genus, its anatomy and morphology, were noted by
Olsen in 1898 and Humphry in 1901. These were both studies
of specimens sent from the Pacific coast, but not
collected by the authors. Further anatomical work was
done by Okaraura which was published in 1908.
The Gigartinas of Santa Barbara were listed by
yates in 1901, and collections were made by Mrs. Bingham
during the same period. There are no further publications
of Gigartinaefrom this region which supports a wealth of
Khodophyceae.
The most extensive study of the Rhodpphyceae of the
pacific coast has been made by Setchell and Gardner'*' of the
^ W. A. Setchell, and N. L. Gardner, A Preliminary
Survey of Gigartina with Special Reference toTTS FUTtH—
AiYISTi"CaTyS'p'dCTdS’"'CTTnirVT- " oT~'CSTTT.'"rUbT 'iri 'Bbtr.TdlT"T7T No.
107 '1V33)~.— -----
University of California. Their publications beginning in
1903 cover various phases of the field, including a survey
of the distribution, a study of plants, associations, and
finally extensive work on classification which is still
subject to further revision. Their latest publication,
December 1933, is 1 1 A Preliminary Survey of Gigartina on the
Pacific Coast’ *,^ This is a revision of the species as
taken from the early classification as made by J. G. Agardh.
photographs from Agardh1s work of the original or type
plants were sent to the University of California and these
proved of great assistance in the identification of
related species and their characteristics. Further
detailed history of the species may be found in the
introduction of the discussion by Setchell and Gardner in
their previously mentioned monograph of 1933.
Other recent contributions to our knowledge of the
genus are in thesis form or in monographs. "The Ecology
of Point Firmin'1, by Couch in 1915 contains four of the
p
Gigartina then common in that area. Heil, 1932,
emphasized a floristic study of the more common of the
^ V/. A. Setchell, and H. L. Gardner, A Preliminary
Survey to Gigartina with Special Reference to Its Horth
American Species ("Univ. of " ’ Calif .'"Pub . in ‘ B’ ot. Vo’ l "IV, ’
Ho. T O , 1933).
2
E. B. Couch, The Ecology of Point Firmin, (Thesis,
U. S. C. Dept, of Botany. 1915)"*""
’ 'Marine Algae of Santa Monica Bay”, and Miss Parks, 1952,
in her survey of the Anaheim Landing to Laguna Beach
area,'*' listed various members of the genus Gi gar tina of
the respective areas studied. These theses do not treat
of the less familiar species, but include mention of the
conspicuous forms such as Gigartina spinosa., now called
Gig artina eatoniana, Gigartina canaliculata, and Gigartina
horrida, now Gigartina leptoryncnos, which were found in
the respective areas studied.
A monograph of interest for comparative study and .
description of species is Kylin’s (1925) paper, on l f The
t
Marine Algae of Friday Harbor, L'ashington”. Also, the
monograph by Sjodsedt (1926), a recent anatomical , and
descriptive study of Gigartina tweedii, not a Pacific
coast species but similar in its vegetative structure to
Gigartina canaliculata. Throughout the survey of source
material on the genus, many details of the study are
lacking, permitting a vast field for further^rese-arch/. ‘ *
The morphology of the local species is very incomplete,
while nothing seems to be known concerning their
periodicity.
1 E. I v l . Parks, A Geo-botanical Survey of Selected
Groups of Marine Algae, (Thesis', U,’ t>. C. Dep'tT o'f Botany.
i9ih):
P
L. G. Sjodsedt, Floridian Studies, (Lund. 1926).
7
Periodicity in Algae
The periodicity of any plant, as has been noted, if'
annual, refers to the regularity of' its recurrence, while
if perennial it refers to the recurrence of reproductive
structures. The Khodophyeeae are in many cases perennials,
being capable under favorable conditions, of living for more
than one year. Nevertheless to maintain life under the'
conditions to which they are subjected in their environment
of rocks and surf, they must be abundant. The G-igartinae^
of the southern California coast are at their height in
number and size during the summer and fall as is true of
other algae. The periodicity in recurrence of reproductive
structures is easily recognized in certain species of
Rhodophyceae because of the marked variations in individual
plants bearing differentiated fruiting, ramifications. Such
plants show differences in color, texture, size, shape, as
well as the si^e and number of proliferations. Knowledge
of periodicity is of particular importance in plants of
value as sources of food or chemical materials, for to
conserve the plant life they must be harvested during those
periods which will not exterminate them, A complete life
history could best be secured by growing the plants in the
laboratory, since no adequate survey of them is possible
because collecting periods of necessity depend on low tides,
and as these species grow low in the littoral zone. The
number of sterile juvenile plants is also a question to be
considered, for during certain periods of the year they are
very abundant, but so inconspicuous in size that their
classification is doubtful unless a sufficient number be
gathered to compare with older and sometimes fragmentary
mature specimens to be found during the same period.
Biological and Economic Significance
Biologically the C-i gartinas are significant as one
of the most conspicuous of the Khodophyceae along the
coast, They provide an anchorage and food for limpets and
periwinkles as may be observed by the numerous rounded
scars on the older plants and the frequent occurrence of
animals among the plants. Certain species, particularly
Gigartina leptorynchos and Gigartina canaliculata are
frequently an entangled mass of fronds due to flat worms.
Many minute algae used by small marine animals as food
are also eplphyticnon.the Gigartina® . However, the fixed
plants are considered indirect in their provision of food
for higher forms of marine animals as these may be feeding
on microscopic masses of plants and animals living on
such of the larger algae,
A few species of the genus Gigartina have been
used as food, since their gelatin content is high, and
their anti-scorbutib vitamin^ content significant. As a
D. K, Tressler, The Wealth of the Sea (Century
Co. 1927).
food they chiefly provide bulk, their protein and carbo
hydrates being meager, and only partially digested by man or
animals. Many of those of a deeper red color are slower to
bleach than varieties containing more green and brown
coloration. Two varieties are used by the Chinese;
G-igartina heImintrochorton as a vermifuge : it is a species
somewhat like Gigartina canaliculata, while Gigartina tenax,
provides a glue and varnish.^ The latter is also used by
the Japanese in transparencies. At present the economic
value of the Gigartinaas is practically unexplored. The
principal difficulty lies in the slow and expensive process
of preparing the product for market, requiring elaborate sea
going equipment for harvesting. Further research into the
value of the algae to man would probably make this expense
justifiable.
HABITAT RELATIONS
Places of Collection
The genus Gigartina as studied along the Pacific
coast shows a wide variety of species and a general
distribution. During the past two years collections have
been made at scattered points from Monterey to San Diego
Bay. The collections from this extensive coast line in
California provided an abundance of material including all
possible, variations, but due to the dissimilarity of these
. H. . . . .Harvey, Lectures on Marine Algae (Smithsonian
institute. 1 8 5 6 ) . --------- 1 ---: ■
10
areas and the modification of species due to environment,
only those collections made along the southern California
coast south of Point Conception in San Luis Obispo County,
through Santa Barbara, Ventura, Los Angeles, Orange, and
San Diego Counties will be considered in detail.
The most extensive collections were made at several
of the stations. Those algae from the. Santa Barbara area
were gathered about one-half mile beyond the breakwater,
and up to Point Goleta. This region supports a wealth of
red algae and Gigartina collected here were large : the
area is deficient in several species common farther south.
vhere is usually a mass of drift material along the beach
but the best specimens were obtained during very low tides.
All of the forms included in this survey were found at
Topango Beach, three miles northwest of Santa Monica. The
specimens gathered here were smaller than those found
elsewhere and because of the rounded, less jutting rocks
were difficult to collect except during the lowest tidal
periods. The majority of the observations were made at
Vhite Point, one mile west of Point Firmin, San Pedro in
Los Angeles County. This station is rich in the growth
of a variety of algal flora and four species of Gigartina
can be gathered here during any reasonably low water.
The last station of importance is the Crescent Cove area,
five miles vrest of Laguna Beach in Orange County. Three
species are available at this point and the rock
of
formation,, as is true, of -that’ Santa Barbara, is similar to
11
that at White Point.
Geography and Rock [Formation
Geographically the entire area represented "by
these collecting stations lies in what Setchell and
Gardner-*- term the sub-tropical zone. It is characterized
by the presence of many of the larger Melanophyceae and
other warm water Rhodophyceae. These are limited by
point Conception on the north and by Magdalena Bay, Baja
California, on the south. It is also to be noted that
changes in algal flora take place with every five degree
variation in temperature, a fact that explains the
variability within this zone as within a greater area.
The shore line at each station faces south to south
west. The rock ledges and tide pools on which the algae
grow are continuations of the strata seen in the over
hanging cliffs, some 50 to 100 feet above the water.
These cliffs have been worn until flat shingle or even
stretches of sand beach are found between their bases and
the brownish red sandstone supporting the algae. These
rocks have undergone long periods of erosion, only the harder
rock being left. The erosion gives a ragged appearance to
these regions» Tide pools are common, but are evidently
■ * • V;. A* Setchell, and N. L. Gardner, Marine Algae
of North-western America (Univ. of Calif. Pub'in“ Bo£•
TolT'I' T'l’ U'OS)"' p . ”155=170
12
less favorable to the growth of Gigartina than the deep
fissures as well as exposed surfaces of the outer ledges
of sandstone, or conglomerate.
The area most favorable for Gigartina at all
stations is the so-called littoral zone, the strip be tv/e en
low and high tide marks. This area is extended five feet
vertically downward below low water level, according to
1
Kjellman. The latter area may also be termed the
submerged littoral region. Species of Gigartina are found
throughout the entire area from the upper littoral to the
sub-littoral zone.
The probable reason for the abundance of plants in
the littoral belt is not only the provision of a rocky
anchorage for their holdfasts, but the action of the waves
bringing a larger volume of water in contact with the
plants than would be possible in calm areas. Prom moving
water the plants secure their necessary supply of carbon
dioxide, which is essential to build up the plant tissues.
Rapid changes in salinity of the water and temperature are
not well endured by the Rhodophyceae and it is notable
that their only period of day-time exposure, when the sun
would be damaging, occurs during the winter months when the
plants are either inactive, or immature. The average
D. S. Johnson, and H. H. York, Relation of Plants
to Tide Levels (Carnegie Institute. 191517
IS
salinity for the region studied is in the deeper water;
35 per 1000 parts of sea water with a specific gravity of
1,0260.^ This degree of salinity may increase during
exposure and evaporation of water in tide pools at low
tide, resulting in the exclusion of the Glgartina%,
Tides and Currents
The principal currents affecting the plants of the
southern California coast are the California Current, and
at times the Japan Current and the Mexican Current, As a
result of these currents the water is warm and the
variation of temperature slight, never more than fifteen
degrees Centigrade "between seasons. The algae inhabiting
warmer seas are of different species than those of colder
waters, so the sub-tropical temperature is a factor in the
distribution of algae found in this region. In colder
seas or higher latitudes all the vital processes of marine
plants become retarded.
The tides are the periodic variations of water
level due to attraction of particles toward the moon and
the sun. The tide tables used in these collections were
o
from the United States Coast and Geodetic Survey.
Sir J. Murray, The Ocean (Holt Co., 1910).
^ Pacific Coast Tide Tables (Dept, of Com. U. S.
Coast and 'Geodetic Survey, 1932, '1933, 1934).
14
The maximum tide at which specimens of all three species of
Gigartina can be collected in sufficient numbers is a plus
1,4 foot tide. However, all tides of minus 0,5 to minus
1,7 feet are far more satisfactory as a wider collecting
'field is available. Frequently collecting was handicapped
by the surf during an otherwise favorable period.
Besides the major tide and current problems to be
considered, the suction upon the algae of receding waves
and disturbance of the currents set up by intervening rocks
are factors in determining the locations of the plants.
There are also off-shore winds causing the rise of waves
and upwelling of deeper water which affect the anchora'ge of
individual plants and yet may benefit the plants through
the aeration of the water.
These are but a few of the factors affecting
competition and the struggle for existence among the marine
plants. But as the tides have been found to be an
essential element in the reproductive cycle of Gigartina
and other algae it is notable that the plants do not grow
in calm water where their struggle against the sea might
be lessened.
Algae Collected
The species of Gigartina which were collected at
the four different stations vary somewhat in their
distribution with respect to the littoral and sub-littoral
zones. Gigartina canaliculata (Plate III), perhaps, the
most hardy of the species, occurred in the middle littoral
zone, ordinarily on exposed or precipitous ledges. This
plant apparently can withstand both exposure and a greater
force of the waves except during the late fall and winter
months, than the other species studied. Gigartina
canaliculata is whip-like in character and offers little
resistance to the water. Gigartina leptorynchos (Plate IX)
a deeper green alga, is found with Gigartina canaliculata,
tout extends its growth.further toward the lower limit of
the littoral zone and prefers more protected areas of the
rock fissures and ledges. Both of these plants are rare
at Santa Barbara. Although the latter is not common at the
La Jolla station, they are both abundant at all other
stations. Gigartina canaliculata often forms solid green
masses on the rocks,
Gigartina. papillata J. G. Ag.- is irregular in its
appearance occurring high in littoral zone in Irregular
inconspicuous tufts of reddish brown, on the protected
shore side of rocks or in fissures. This species withstand
periods of exposure, reviving quickly when again covered
by the rising tide. Gigartina eatoniana (Plate I) is
similar to the preceding species In its dark red color,
but is somewhat different in its habitat. Gigartina
eatoniana occurs in the lower littoral and upper sub-
littoral zones, V/hile Gigartina eatoniana was common at
16
all the stations studied, Gigartina papillata was most
abundant at La Jolla, a few plants were gathered at Arch
Beach near Laguna, some scattered plants at -Ahite Point,
and it has been noted at Topango Beach,
Gigartina vplans C. Ag. is not common although
free floating specimens have been gathered at Ventura,
Other species, Gigartina binghamiae Bingham, Gigartina
harveyana Harvey, and Grigartina microphylla Harvey, have
been collected at Santa Barbara and La Jolla, and although
abundant at those stations these plants are not common at
the other collecting stations. Gigartina serrat a . Gardner,
similar to Gigartina canaliculata, only stronger and larger,
is abundant at Balboa palasades, but absent at the other
stations . Another endemic species, Gigartina armata
was collected at Crescent Cove, Laguna, All of these
species will be described later in a further discussion
of other species.of the genus Gigartina.
COLLECTION AND EXAMINATION OP SPECIMENS
Collecting Periods
The collection of the algae studied was dependent
upon the tides. Specimens were taken at monthly intervals
during tides low enough to secure at least the three
species ; Gigartina eatoniana, Gigartina leptorynchos, and
Gigartina canaliculata (Plate I, II, III), The mode of
collection was similar for each month. A minimum of 100
•17
plants of,each species was taken at random from a small ^
area, within a fifty to a one hundred foot zone’ at any one
of the available stations. Since the reproductive structures
were being studied, fresh killing fluid was frequently
taken to the collecting station in separate bottles and small
pieces from plants' of the three species emphasized.in this
study were placed in these bottles until ready for U3e.
Otherwise, the plants were pressed within 12 hours after
collecting and dried on the electric drier. During the
early part of the-survey the plants were examined for
reproductive structures when they were placed in the driers,
but as this system did not permit a recheck on the
individual specimens, the final records were made from
dried material filed and checked after drying. The
disadvantages of this method are twofold, however. First,
the shrinkage of plants, which even with careful drying,
may reduce them in size and cause a corresponding decrease
in the size of the reproductive areas, Secondly, the
plants because of their high mucilaginous content dry
slowly, while the tetrasporic and ontheridial plants that
have a decreased number of cortical cells as compared with
cystocarpic and sterile forms, easily decompose under slow
drying conditions.
Method of Study
A hand lens was used to identify the fruiting
18'
structures of 100 plants of Gigartina eaton!ana and 50 each
of Gigartina leptorynchos and Gigartina. canallculata.
These results are shown in Tables I, II, and HI* One
hundred plants of the former were used because this is the
usual genetic number, while fifty plants of the other two
species were merely checked as a matter of comparison and
consequently less time was spent on their structures, The
reproductive or sterile condition of each plant was
recorded, together with its station, period or date of
collection and current or corresponding tide level. The
individual plant was dried, examined, filed in an old
magazine and given a serial number. This procedure pro
vided for a simple method of rechecking the plants later
in case of any question. A second and sometimes a third
recheck of plants were made. The method of examination
was to remove a questioned structure or a small fragment
of the plant tissue for further observation. These
fragments were placed in sea water for fifteen minutes
allowing them to regain their normal turgidity and
flexibility that they might be sectioned by hand or with a
sliding microtome. The sections were cut 20 to 30 microns
thick and were then mounted under the compound microscope.
Frequently it was necessary to use iodine or methylene
blue as a stain, although plants carefully dried regained
approximately their normal colors and cell contour when
treated In the above manner.
r
19
Plants under question can thus he determined as to
their place in tho life cycle. Many of the specimens
doubtfully noted as antheridial or sterile on re-examination
showed immature tetrasporic, or cystocarpic tissue. These
structures became evident from an early period in the
development of the proliferations. Some plants that are
difficult to determine were analyzed by a careful exam
ination of the old proliferations on the portion of the
frond just above the stipe. This procedure often results
in placing such specimens in their proper group*' ' Although
numerous attempts were made to develop a satisfactory
technique of imbedding the acids in a fixing solution and
the xylol in the paraffin always made the plants too brittle
to be properly sectioned. A modification of the usual
paraffin method-*- was necessary. The specimens stained with
methyl violet, basic fuchsin, or the stains previously
mentioned were in the best condition for examination by the
following method which, although sufficient to determine
the presence or absence of reproductive structures with
reference to periodicity, is open for further improvement.
The use of glycerine to reduce brittleness gave some
promise of success. The tissues were rapidly dehydrated by
leaving them in e^ch alcohol of the 20, 40, 60, 80, 95, 100
series. The material shrank or became distorted although
C. J. Chamberlain, Methods in Plant Histology
(Univ. of Chicago press, 193TJT* p7 £f ! ’ 7-251.
20
the mucilage did not all disappear from the madullary
tissue. The presence of mucilage in the tissue after
dehydration was observed in fresh material sectioned and
run through the series of alcohols as well as in material
cut in suitable sizes and embedded. A more gradual process
Of dehydration did not cause as rapid hardening of the
plant tissues, but the end result is similar to -that of the
above procedure. The most favorable embedding method,
although not ultimately successful for permanent mounts,
was obtained by the addition of two drops of glycerine to
the first three alcohols and three drops to each of the
remaining alcohols. This prevented a complete collapse of
the delicate cellular tissues through hardening. The
plants were then embedded in 52° paraffin.
Superficial examinations of the plants essential
only for a paper on periodicity iQre thus made through a
study of free hand and microtome sections of fresh and
dried material. The morphology of the southern Califox'nia
G-igartinas on the other hand is a field for further
research.
Monthly charts were made covering a period of one
year to show the frequency of occurrence of the different
kinds of individuals of each species. Among these
individuals the gametophytes were always dioecious and
similar in size to the tetrasporie plants. Therefore,
there were fo\ir kinds of individuals; the male or
21
anther!dial, the female or cystocarpic, the asexual or
tetrasporic and the sterile. Tables I, II, and III, were
made from these charts for comparison of the results.
The two species in which only 50 plants were examined
each month show interesting parallels in the appearance of
their reproductive structures with the variations in the
frequency of occurrence of similar structures on Gfgartina
eaton!ana. Further notes on the individual plants will be
discussed under the observations on the separate species
which follow.
General Observations
Many important observations were made while
collecting the specimens. These observations deal
particularly with the size and color of the plants in
relation to their habitats, regeneration, the effect of
short storage periods on reproductive structures and
finally monthly variations.
Some features of size and color of the plants are so
obvious that they could not be easily overlooked. The
plants of all species are smaller when growing high in their
zone or when in well exposed areas. The finest plants are
usually obtained from the shore side of ledges running in
such a manner that their outer surfaces break the force of
the waves. All plants become lighter in their natural
color and most plants are conspicuously green when partially
22
buried, i. e., when the stipes and fronds are “ buried by
sand. Gigartina leptorynchos is some times found grooving
in sand, but this is a rare occurrence for the other
species. The change in color mentioned above v/as
particularly to be noted at Crystal Cove near Laguna, where
all the fresh plants were generally of lighter color than
those at the other stations. This may be accounted for
by the fact that there are periodic shifts in the current
due to storms which cover areas of the rocky coast with
sand six inches to two feed in depth, or at other times
washing out the sand and fully exposing the rocky ledges.
Plants growing in deeper water also tend to become less red,
or a yellow to greenish red in color. This feature is
particularly noteworthy at the Laguna stations.
During the spring and early summer it was observed
that regeneration occurred among the larger Gigartinae
while small species, such as Gigartina. leptorynchos and
Gigartina canaliculata, grow from small young plants and
rarely regenerate from worn blades. The larger forms, like
Gigartina binghamiae and Gigartina eatoniana, show re
generation from the portion of the frond above the stipe.
Erom this area numerous proliferations occur, usually
becoming dichotomous in their habit of branching. These
plants often show torn tips which regenerate by sending out
one or many small proliferations, or heal and eventually
may bear fruiting ranuli. The most interesting form of
23
regeneration is the wearing or eating out of small oval or
rounded areas in the plant frond which heal and often show
a circular rim. hearing fruiting bodies. This is
particularly true of small wounds in the cystocarpic plants.
When plants were left in collecting dans or rolled .
in newspapers for three days in such manner that the plants
were neither too damp nor could not lose the natural
moisture held by the mucilaginous cortex, structural
changes occurred. All the fruiting ramifications became
larger and more conspicuous, the tissue, probably due to
its covering of mucilaginous cells, does not break down
within this period, but leaves the structures in splendid
condition to be studied, A longer time however under
these conditions results in disintegration.
Special observations made during collecting periods
on the individual species studied furnished data related
to periodicity, Figures 1, 2, 3* During January the
cystocarpic plants of all the species studied are fewer
than the tetrasporic. The fronds of the latter are older
and in poorer condition,, but complete and not battered
nor worn by the waves. The tetraspores were numerous,
appearing in small red swellings on the proliferations
from the main filament of the plants. The fruiting ramuli
Gigartina eatoniana drop off readily while drying.
Many of these fruiting organs are open, while some are
bleached showing dead cell tissue. All species of Gigartina
24
are more scattered in January within their zones than in
summer. The majority of plants collected during the late
fall, i. e., November and December, had torn fragmentary
lobes of their former fronds. There are great numbers of
small sterile plants of all the species, collected which
are but one-half of three centimeters in length and in
close compact mats on the rocks. These are far more
numerous than the mature plants, so some must be destroyed
before maturity.
The collections during February were difficult to
gather due to stormy weather causing a higher surf. There
was little change in the plants from those collected
during January,, growth being retarded either by low
temperatm1 e of the water, or by the storms prevalent
during this period of the year.
In March the number of sterile plants was still
notable and some began to show the formation of fruiting
areas. There are few large specimens to be taken during
this period, though more rapid growth occurs between March
and April than during the preceding/ month. In April the
plants are thin and of a light color, but variable in these
characteristics at different stations. The antheridial and
young tetrasporic plants degenerate rapidly while drying
because of the smaller layer of cortical tissue.
During L I ay and June all species show a distinct
growth. The contrast between general conditions of plant
25
life for the two months is slight, but other variations
are shown in individual species studied. The number of
small plants of-the sterile type are few and the fruiting
ramuli become more distinct. These months seem to be a
transition period for plant forms as is shown in Figures
1, 2, and 3.
July and August may be noted with the early fall
months as the height of plant growth in number and siae of
mature plants and the character of individual specimens.
The characteristic branching habit and development of each
plant are marked as well as its associations. Host
specimens have well differentiated fruiting bodies, re
quiring less microscopic study at this time of the year.
The above period of plant development continues
until October of November, depending on the occurrence of
stoi’ ms, for as the year closes the plants reach their
maximum period of growth and pass beyond it into a
decadent period when the cystocarpic and tetrasporic plants
decrease in number. Storms bring a partial or complete
destruction on such plants. During November to Hay, 1932
to 1933 there were a gx^eater number of mutilated plants
than at any other' period, as is also true of 1933 and 1934
for the same period. The species less subject to damage
are Gigartina leptorynchos and Gigartina papillata, while
Gigartina eatoniana, Gigartina canaliculate and Gigartina
26
binghamiae are readily broken by storms. These general
observations are the only ones regarding periodicity which
are not included in the discussion of the individual
species.
RESULTS OP SPECIAL OBSERVATIONS ON THE THREE SPECIES
OP GIGARTINA
Gigartina. Eatoniana J* Ag»
Detailed observation of* the individual species
collected from month to month for over a year gave an
opportunity to note variance In the habits of the plants
In their environment as well as a more detailed study of
their individual differences of structure. These
observations deal primarily with the features of the species
relating to periodicity, i. e., the appearance of eystocarps,
antheridia, tetraspores and sterile plants,
Gigartina eatoniana lacks a detailed description
although listed in the Herbarium Agardh at the University
of Lund where type specimens of the first identified
plants are to be found. It may readily be confused among
Gigartina spinosa (Kuetz) Harv., Gigartina harveyana and
Gigartina volans. Although not listed by Setchell and
Gardner as common In southern California^ the plants used
in this study were determined by the assistance of Dr,
Gardner from specimens collected at the major stations,
Gigartina eatoniana belongs to the first series
designated as "A” by Setchell and Gardner,^ in subgenus 4,
- * • W. A. Setchell, and N. L. Gardner, A Preliminary
Survey of Gigartina (Univ. of Calif. Pub. in~Bot. Vo'l'. 17,
Nd;"TU.”T93Tn— P.“ 271.
2 Ibid. p. 264.
28
or Chondraeart,thus Kuetz » This subgenus is designated by
pinnated forms with scant to abundant superficial as well
as marginal fertile branchlets, i, e., pinnately
tetrastichoid (Plate I).
Prom the study of the species, Gigartina eatoniana,
for this paper, a further description is necessary. The
fronds are companulate, 2 to 60 cm. in length and 2 to- 12
cm, in width, with a tapering toward the tip -which extends
to a point in young plants, but to rounded tips in old
plants. The character of dichotomous branching is not
always present but is well defined in most plants. The
plants are none to several times branched. Branching is
variable occurring within 3 cm. of the stipe to or near the-
tip of the frond, the fronds bear many to few proliferations
v/hich are not decurrent as in Gigartina spinosa. The
stipe is 1-5 cm. in length; oval in cross section and
supported on a discoid holdfast. The holdfast may bear
young sterile or mature fronds varying in number from one
to thirty. All fronds rarely mature for many break from the
holdfast leaving clear oval pits or scars. The stipe joins
the frond at a frequently crude triangular flattened base
supporting branchlets which vary in size and shape. This
area may be branched from an axis, or when lacking the plant
frond narrows into the stipe. Mature plants bear
fructiferous ramuli which are lacking on holdfasts, stipe
and base of frond, but may appear elsewhere on the blade.
Tetrasporic ramuli all pointing upward toward the tip of
plant, are 1-5 mm. in length and of varied form; some are
rounded and others spiny, bearing chains of one to eight
red masses of sori, Plate V. The cystocarpic ramuli are
branched or single; never more than three borne on a single
1-2 mm. stalk, Plate IV. Some cystocarps are echinate,
others are rounded or pitted, Antheridial plants are not
numerous, and are differentiated by their thinness of
fronds which may bear numerous proliferations from the
surface of the frond or remain plain. The tetraspores are'
inconspicuous except in a microscopic examination; these
are best determined In fresh material. In all fruiting
plants the ramuli may be borne on branched or unbranched
fruiting pinnules of varied length at the border or on the
flattened surface of the frond,
Gigartina eatoniana may be collected in scattered
areas in the lower littoral zone, sometimes extending
into the area covered at low tide, and frequently higher in
the zone being protected by an overhanging fringe of
Pelvetia, Egregia, or other Melanophyceae. More frequently
it Is to be found in association with other "-species of
Rhodophyceae and particularly the other species of Gigartina.
The plants cling to their rocky base more firmly than some
of the other species and must be removed with a sharp
instrument to preserve the holdfast.
Several variations of the plant were noted during
30
TABLE I
GIGARTINA. EATON I ANA
Date of Tetra Cysto Anther- Ster
Collection sporic carpic idial ile
March 26, 1933 28 28 6 38
April 22, 1933 26 27 1 46
May 3, 1933 26 39 15 2,0
June 24, 1933 16 51 10 23
July 1, 1933 12 .54 21 13'
August 26, 1933 29 45 7 19
September 16, 1933 31 43 13 lo
October 29, 1933 45 47 2 6
November 18, 1933 40 37 2 21
December 29, 1933 41 35 2 22
January 13, 1934 47 33 2 18
February 16, 1934 38 42 10 10
Total number of plants examined each month -- 100.
31
its collection; these variations are only recognized, when
a large number of plants are examined. One example of
such deviations from the usual plants is in the coloration
of the young cystocarpic plants that are of thinner texture
and less red in color xVhen collected in the early spring
than those collected later in the season. The cystocarps
arise from terminal and lateral proliferations as well as
on pinnules. Some of these develop as white tips which
resemble mature cystocarps developing from cortical tissue.
Old plants remaining over from the previous year are torn
but are found to bear new cystocarps on old fronds or on
new branchlets developing from the remaining portion of the
plant.
The carpospores, as are shown in Plate IV, develop
in the center of the cystocarp in clusters of over one
hundred. These carpospores are embedded in a spongy mass
of tissue which holds them in place, but is readily broken
down on sectioning. The carpospores are also differentiated
from the mass of cartilaginous medullary cells by which
they are surrounded. In one square centimeter of the
frond of a mature cystocarpic plant were found 25 to 30
cystocarpic proliferations. These vary from those with
echinate tips to those that are rounded or pitted, Plate
IV. From this identical area of the frond all of the afore
mentioned structures were sectioned and examined under the
4 mm.objective of a compound microscope. They appear to be
nearly identical. The cystocarps which are pitted
contain more deeply colored mature carpospores than those
which were smooth or on the surface. Pitted cystocarps
placed on a slide and pressed with a cover-slip forcing
the carpospores from the capsule, or .-when sectioned and
examined, show ruptures always at points of the noted
indentation. On further examination these areas are
found to have one-half or less the usual number of cortical
cells, which are almost completely lacking at this point
of the cystocarp. The medullary layer appears in its
usual thickness about the other surfaces of the carpospore
mass, plate IV,
The cystocarpic plants occur more frequently than
the antheridial or tetrasporic plants throughout the
entire year. This is shown in Table I and graph, Figure
1. Cystocarpic plants are lower in the frequency of
occurrence in November, December and January. In
February due to increased temperature the plants-show
indications of growth but fell to their lowest number in
March and April, (Figure 1) probably due to the storms
causing further destruction of some of the older plants.
One reason for an advance in the number of cystocarpic
plants out of the total of 100 plants checked dxiring
February, is the destruction of numerous tetrasporic
plants by storm and the fact that the cystocarpic plants
remaining are the old plants that survived, Figure 1,
Number^
1
B8S»SSS5SS^»SSSSSiiS!Q»SSB
“ Months of the year
'Figure !•
GRAPH SHOWING PERIODICITY IN GIGARTINA EATONIANA
Cystocarpic
Antheridial
■>— >— >—
Tetrasporic
—< j » —-©™- gj-gr-' ' ■
Sterile • : >
34
Following this period there was a marked increase in the
production of cystocarps with a maximum number in July
and a fluctuating decrease to the mean from October to
November, Figure 1. The check of three or more years
observations with a closer check on the number of sterile
plants found from December to April would probably form a
more perfect record.
Tetrasporic plants are noticeably thin but vary
greatly in color and in the number of fruiting
proliferations. In an area of one square centimeter on a
typical plant surface there were ten tetrasporic papilae.
Tetrasporic plants readily decompose when they fail to dry
rapidly, that is within 3 to 5 days after being gathered.
Y/hen this disintigration occurs it begins to show at the
tips on heavily fruited areas of the fronds. These
structures are also readily subject to mildew, as are
other forms of Gigartina eatoniana. During certain
periods of the year, notably summer, they show old
tetrasporic proliferations on the base of the old frond
areas with sterile or budding tetrasporic sori on other
portions of the plant.
Antheridial plants were the most confusing type to
distinguish. The antheridia are as in other Rhodophyceae,
non-mo tile. They are developed according to Sjodsed.t'1 '
■ * " L. G. Sjodsedt, Floridian Studies (Lund. 1926).
35
quoting Svedeleus, r f from cortical cells which are converted
into more or less ramified systems which in their turn form
spermatangia". These structures were best observed in
fresh material, but were also seen in sectioned dried
plants prepared from material placed in salt water. They
stain to a recognizable degree with iodine, the cell walls
becoming more definite, Plate IV* These observations
vary from Hoydt’s conception of the sntheridial structures
in which he says;"*- "antheridia are usually in patches
more or less widely distributed over the thallus, usually
produced singly on a three celled carpogonic branch
associated ?/ith the auxiliary cell into a short process,
the latter then giving rise to the gominoblast consisting
of a tuft of filaments richly branched in all direct!ons".
Hoydt's statement also varies from Dr. Gardner's
description of antheridia as being born on separate plants
which usually are in conspicuous, fruiting proliferations,
the notably thin plants already having been mentioned.
The literature' on the subject is lacking, and of the many
species reported the antheridial plants were noted, as
unknown, or not described.
The number of antheridial plants as discussed In
this paper is still somewhat questioned although they have
1 W. D. Hoydt, Ilarine ' Algae of Beaufort, N. C. (Bull,
Bureau Fisheries, Vol. XXXVI. Doc . M&O)..
been studied carefully and only definitely determined
plants listed, Plate VI* Because of Hoydt’s observations
some fifty plants of the type described were sectioned
and observed under a magnification of 450 diameters, but
no antheridia were noted near cystocarps or their echinate
auxiliary cells, Plate VI. The structures drawn were
taken from plant types such as those noted by Gardner
and Sjodsedt. The periodicity of the antheridial plants
follows particularly that of the cystocarpic, although
they are fewer in number, the low peak in the frequency of
occurrence being reached from November to February, ?/hereas
the antheridial plants were most numerous in August, but
the larger frequency number was maintained from May to
October, which was also Indicated as true of the
cystocarpic plants.
Probably the greatest variation of structures with
respect to periodicity of Gigartina eatoniana appears in
both the sterile and tetrasporic plants. The latter
plants are notably more numerous throughout the year than
any others except the cystocarpic. The tetrasporic plants
are most numerotis in October, November, December and
January, when cystocarpic and antheridial structures and
sterile plants become inconspicuous or few. VJhile the
total number of plants begins to decrease in February
reaching the minimum from July through September, Table I.
37
The sterile plants are conspicuous as iji&ieated in
the graph. Plate I and Figure 1, by their fluctuations
reaching their greatest frequency from November to April.
The drop in their frequency number as has been -previously
noted may be due to the method of collection, for they
are readily lost in drying, or may be overlooked while
collecting because of their microscopic size. In structure
these plants are most commonly a single lobed thallus, but
in some ca.ses are the mature plants in miniature, at times
being of considerable size, up to some 10 cm. in Gigartina
eatoniana. A sterile plant may readily be compared with
those bearing fruiting proliferations by observing sterile
fronds on a large holdfast of a mature cystocarpic or
tetrasporic plant,
Gigartina leptorynchos J. Ag«
This species has undergone many revisions in its
place in algal literature, the present name being that
listed by J. G. Agardh in 1885. .It has also been known
as G-igaPtina mollis J. Ag. and Farlowia mollis Harv. et
Bail., the most common name, that of Gigartina horrida
Farlow, given to the plant in 1891^, a species name which
C. L. Anderson,. List of California Marine Algae
with Notes (Zoe, Vol. 2. 1891). f. '217-225.
38
continued until Setchell and Gardner began their
revision of Gigartina about 1931. Gigartina leptorynchos
r r T ' ■ V ' T " " i r “ “ ' ‘ r .J r ~ ...i
belongs to the series "A" and sub-genus 4, or Chondraeahthas,
together with Gigartina eatoniana and is illustrated in
Plate II,
The specimens collected show a great variation. In
size, color and texture which not only occurs at the same
station but is more pronounced among the different stations.
As previously noted this species is most abundant in the
subtropical area from Ventura to Dana Point, being almost
lacking at Santa. Barbara and decreasing In number south to
La Jolla. The size ranges from 2 mm. to 30 cm. in length
and 5 to 15 mm. in width. then young, or In certain
generations the flattened narrow irregularly pinnate frond
occurs. In older plants the frond is covered by short
cylindrical pinnae and the frond thickens. These pinnae
are 15 mm. In length or less and branched or unbranched.
They may bear tetraspores, cystocarps, or remain sterile.
Gigartina leptorynchos Is brown, green to black-green In
color for most plants, rarely showing a true red. Fresh
plants held to the light may show a little red-toward the
base of the frond, or on the stipe.
Gigartina leptorynchos grows in association with
Gigartina canalicxilata in the littoral zone and Is found in
scattered masses. It is noted more frequently in tide pools
than the other species. The larger plants are often
protected by Felvetia fastlgiata, or Hesperophycus
harveyana on the sides of ledges, or the floor of
fissures. This species apparently will withstand pro
longed exposure. ■ . .
The stipe of th'e plant is short usually within 1
cm. on the typical holdfast. The plants tend to grow in
tufts with ten or more fronds branching dichotomously or
otherwise. Gigartina. leptorynchos is less readily
separated from its holdfast without damaging or separating
the fronds, than the other species. Its plant fronds are
compact''and firmly affixed to their base.
The cystocarpic plants are most numerous in June to
November, but a few appearing from December to i . I a y are,
typical of the genus Gigartina, with respect to seasonal
distribution (Figure 2). The carpogonia are borne on
fruiting ramuli which most frequently appear on branches of
the proliferations, but may grow from the body of the
frond. The cystocarps are usually echinate, bearing
commonly one rarely more than three carpognia on a
proliferation, Plate II, Its vegetative structure is
similar to that of Gigartina eatoniana with the exception
of a thinner layer of mucilaginous medullary cells and a
less abundant cortical layer.
The tetrasporic plants of C-igartlna leptorynchos
usually have thicker longer proliferations than those which
occur on the cystocarpic plants, Plate II. The frond Is
40
Humber of plants
III i I I I I I ITT
'Months of the year
Figure
GRAPH SHOTTING PERIODICITY IN GIGARTINA LEPTORYNCHOS
Cystocarpic ( ( > [ , ( , , ,
Antheridial ; ; ; . .
Tetrasporie^^^
Sterile ____
41
characteristically heavy. The fresh tetrasporic sori are
pink to clear red in color occurring in regular masses
from • § • to 1 mm, in size. These fruiting ramuli are
conspicuous throughout the year, but re^ch their peak cf
development in number in April, Table II, They usually
display one to six, rarely more, sori on each
t
proliferation,
Antheridial plants are thin' with fewer pinnules, the
antheridia occur in masses under the outer cortical layer,
Antheridial plants are also of a lighter green color, to
olive green, but rarely red. These have been
distinguished in a few cases but require fubther morpholo
gical study.
Sterile juvenile plants are of a clear light green
in color with few pinnae and the typical flat frond well
distinguished from that of plants bearing fruiting
proliferations. Growth'in early spring of sterile plants
is rapid, as will be noted later.
A difficulty met in collecting and drying perfect
specimens" of .Gigartina leptorynchos is caused by heris
worms, threading their way between and about fronds among
their branches, sometimes causing a'distortion in the
plant growth and making unentanglement difficult.
This species survived for three months in artificial
sea water, although the plants Increased in size from 3-10
to 20-25 mm. In length, the reproductive ramifications
42
TABLE II
GIGARTINA LEPTORYNCHOS
Date of
Collection
Tetra
sporic
Cysto
carpic
Anther
idial
Ster
ile
March 28, 1933 19 13 2 16
April 22, 1933 22 6 2 20
May 3, 1933 19 6 4 21
June 24, 1933 15 23 4 8
July 1, 1933 11 27 5 7
August 26, 1933 18 21 3 8
September 5, 1933 10 17, 5
IS
October 29, 1933 13 20 3 14
November 18, 1933 12 19 4 15
December 29, 1933 14 6 2 28
January 13, 1934 16 14 0 20
February- 16, 1934 13 7 2 28
Total number of plants examined each month -- 50,
4-3
failed, to develop. All three species of Gigartina
emphasized in this paper were brought into the laboratory-
on stones to which they were affixed, as sterile juvenile
plants, during December and February. Gigartina
eatoniana only lasted two weeks, while Gigartina
canaliculate survived four weeks, compared to three months
for Gigartina leptorynchos as noted above* Table II.
Death of the plants was apparently due to lack of aeriation
of the water. A lowered concentration of salts brought
aboiit by increased addition of distilled water was longer
tolerated by Gigartina leptorynchos than by either of the
other species. Death of the plants occurred by decom
position of the plant tissue starting from the tips. The
plants became mucilaginous and bleached. The latter effect
may have been caused by the position of the plants in a
battery jar in light, but not in direct sunlight at any
time •
Gigartina Canaliculata Harvey
Gigartina canaliculata Harv. has in common with
Gigartina eatoniana and Gigartina leptorynchos the
classification under series ’ ’ A" as noted previously^-, but
1
VI, A. Setchell, and N. L. Gardner, A Preliminary
Survey of Gigartina (Univ. of Calif. Pub. 'in-Bot. KoTI 17,
WoT^TO .™I93377"W"264-265 .
44
is differentiated from’these in its subgenus, ISugigartina.
This species is at present alone in the subgenus and
observation of the plant quickly shows the wide
differentiations between Gigartina canaliculata and the
other species studied.
The species may be described as narrow, being
decidedly compressed; dichotomous or only dichotomous in
lower branchlets. It is illustrated in Plate III.
Setchell and Gardner further describe it as being
ndistichously pinnate and terminating as branches and
branchlets, in sharp aculeae; the cystocarps being borne
singly or on crowded fertile ramull, flat or with one or
more subapical aeuleae.” The average length is 1-12
rarely 18 cm. usually being branched from 1-3-cm. above
the holdfast, the Y/idth is 1-4 cm. The stipe is irregular
but usually more narrow than the frond. The color of the
plant is, olive green to brown or clear green. Both
tetrasporic and cystocarpic areas show red coloration on
proliferations,
Tetraspores appear in sori on fruiting ramifications
pointing toward the plant tip, Sori appear in chains of
2-4 on all surfaces of tetrasporic proliferations. Maximum
^ U. A. Setchell, and IT. L. Gardner, A Preliminary'
Survey of Gigartina (Univ. of Calif. Pub. In“Bot'. "Vol. 37T,
lo7~IU. “19^37^ "ppT 264-265.
L
45
TABLE III
GIGARTINA CANALICULATA
Date of Tetra Cysto- Anther Ster
Collection sporic carpic idial ile
March 26, 1935 15 7
28
April 22, 1933 14 5 31
May 3, 1933 14 8 28
June 24, 1935 19 15 16
July 1, 1933 16
18
16
August 26, 1933 19 20 11
September 5, 1933 15 18 17
October 29, 1933 9 28
13-
November 18, 1935 14 25" 11
December 29, 1933 10 11 29
January 13, 1934 7 5 38
February 16, 1934 10 4 36
Total number* of plants studied' each month — 50
Antheridial plants unknown.
production of sori occurs during March and again in
September, whereas cystocarpic plants are continuously
conspicuous from June through November, Figure 3.
Sterile plants of Gigartina canaliculata are either
of the juvenile type of less branched lighter colored
fronds in smaller tufts or old plants with an entire stipe
but old bleached and broken tips. The bleached tips
occurred in areas where the plants are not bleached through
exposure under ordinary conditions. Sterile plants are
very plentiful from December to May. Table III. These
occur in tufted masses with six or more branching fronds
on each.holdfast. The holdfasts are always small and less
truly discoid than in the other two species of Gigartina.
Gigartina canaliculata occurs high in the littoral
zone and only extends to the border of the belt formed of
Gigartina eatoniana with other red and brown algae * It is
found but rarely at Santa Barbara becoming more abundant
at Ventura, Topango, Palos Verdes, and White Point and
decreasing further south, being in but scattered masses
at La Jolla. V/ith the tendency of this species toward
bleaching and Its rapid rate of drying in the electric
dryer as compared with the other species and because of the
greater plant masses to be gathered in a wide area in any
commonly low tide, it would probably prove of greater
value commercially than any other of the southern California
Gigartina®.
47
- « bi
IK "!
Hr
i r * i
•'Am
i m m t
T'
Months of the year
Figure 3*
GRAPH SHOWING PERIODICITY IN GIGARTINA CANALICULATA
Cystocarpie , ,
T e t r a s p o r i c ^ ^ ^
Sterile______________
It is likely that some of the lighter colored
plants may be proven to bear antheridial structures, but
in the plants sectioned and observed no cells indicative
of antheridia were determined. The description of the
larger species related to Gigartina canaliculata,
Gigartina serrata and Gigartina canaliculata. f. laxa,
- j
as described by Dr. Gardner , do not include descriptions
or illustrations of the antheridial plants in any case.
N. L. Gardner, hew Rhodophyceae from the Pacific
Coast, III (Univ. of Calif.' P u b ' . ' 'in ’ f i o t i . ' Vo I . " T2T7 i - l o . 16.’
TZ277. ~p7 334.
49
CERTAIM OTHER SPECIES OF THE GENUS GIGARTINA
The genus Gigartina includes a number of species,
besides these three described previously that have been
noted along the southern California coast, They vary in
size and extent but none are as wide spread as the species,
Gigartina eatoniana, and some may be considered endemic In
this region.
The largest Gigartina taken during the collections
were specimens of Gigartina binghamiae J. Ag» The plants
of this speciea are a clear deep red to bright red In
color, with a sterile base and stipe, and chiefly marginal
cystocarps. The tetraspores are generally well distributed
on the frond. Antheridial plants are very thin. Mature
fresh plants of the species measure 30 to 45 cm. In width
and 45 to 60 cm. In length. Some plants show a tendency
toward dichotomous branching, but the usual shape, is a
broad continuous thallus with a rounded apex. Plants
have been collected in the lower littoral zone at Santa
Barbara, but free floating specimens have been taken at
Ventura, Redondo, Balboa Palisades and La Jolla; the
latter however are few. Following a severe storm specimens
were found on the shore at Hermosa Beach, still attached
to small stones.
The cystocarpic structures of Gigartina binghamiae
are smaller in comparison to the size of the plant than
50
those of Gigartina eatoniana. The characteristic echinate
n.... ' 1 -T- - 1 — T "....... ' 1 " *
*
spines of the latter are usually lacking on the cerpogonial
branches for the former species. Tetrasporic spines are
usually rounded and do not tend to point as sharply upward,
as those,In Gigartina eatoniana. The data on periodicity
shows the appearahee of all reproductive ramifications at
about the same period as those of Gigartina eatoniana,text
Figures 1, 2, and 3, except In the case of the carpogonia
i
which appear to have the ability to hold over more readily
than those of the compared species. An interesting phase
of these cystocarpic structures is their growth about the
edge of a wound area In mature plants of Gigartina binghamiae.
This feature is common in this species, but rare in
Gigartina eatoniana. Shrinkage of Gigartina binghamiae
while drying is sometimes to one-third of the original
size when fresh, even after careful slow drying, Gigartina
binghamiae belongs to Series B, Magnifoliate^ in subgenus
5, Cheilogigartina described as having thin chartaceous
membranous blades. As it belongs to the group in which
Gigar11 naexaspp-rata and Gigartina harveyana are classed, the
similarity of these species is again noted..
Gigartina exasperata Harv. et Bail., is indicated as
V;. A. Setchell, and I \ T. L. Gardner, A Preliminary
Survey of Gigartina (Vol. 17, No. 10. 1933). p.’ ' 2 ' 7 ‘ 9'.
51
having a relatively thin membranous blace of large size.
The stipe like that of Gigartina binghamiae usually
extends into a broad ovate blade of clear light red color,
but in some few plants the stipe branches . The blades
sometimes reach one. meter in height and one-third meter in
width. This species has been collected at scattered points
from Santa Barbara to Balboa, and may be definitely
identified from the description by Drs. Setchell and
GardnerThey also in the case of this, plant give a
detailed description of the antheridial plants as follows:
nThe antheridia cover the surface of rather slender and
elongated surface papillae, and antheridial plants are
thickly margined with short (1-2 cm. long) ovate lanceolate
pinnates which give it a distinct aspect.1 1 The habitat of
the plant being in the sub-littoral zone explains the fact
that it is found free floating when located at the various
stations.
Gigartina boryi named by Setchell and Gardner may
i
easily be confused with the species, Gigartina harveyana,
formerly named Gigartina microphylla. It is a slender
plant with fronds to 55 cm. in length but rarely more than
six cm. in width. Along the frond appear numerous
1
I?. A. Setchell, and N. L. Gardner, A Preliminary
Survey of Gigartina with Special Reference to Its Kbrth'
American Species ftTniv. of C'sli'f ,~FuxT, iri' 'Bof. “VoIT IT,"
ho TO. 19’ S3 ) . pp. 275-276.
52
proliferations. The marginal fruiting pinnules are
conspicuous, and these may appear at the center of the
frond, hut rarely on the submarginal portion. The
occurrence of this species is from Monterey to La Jolla
though in the southern California area it is most common
at Santa Barbara and La Jolla.
Gigartina armata J. Ag. is marked hy a membraneous
frond and a pure red color. The margins are never
thickened but often excurrent into small pinnules and into
cystocarps smaller than Gigartina spinosa. Except for
the marginal lanceolate pinna© and its more narrow blade
(about 5 cm.) it is very similar to Gigartina spinosa
and Gigartina eatoniana. During the study of the southern
California Gigartinae this species was collected at Laguna
and La Jolla. The variations'between this plant and the
others are so few that it was only accurately determined
from specimens checked with those at the University of,
California.
Gigartina volans J. Ag. has been collected as a free
floating plant at Ventura and Redondo but is listed and
described by Setchell and Gardner as abundant on the
northern California coast and occurring from Oregon to
southern California, Although carefully described it seems
to remain open to question due to the variability of the
individual specimens and to its place of growth. But two
specimens were taken during this study in southern
53
California and these remain open to question as true
species of Gigartina volans.
An interesting species open to much further study is
the form named Gigartina cristata by Setchell, or Gigartina
papillata J. Ag.; but has been suggested as a possible
variety of Gigartina Agardhii. This plant is first
differentiated by its appearance high in the littoral
zone, sometimes' above the Pelvetia. belt, showing its
resistance to drying. The plants are small, 1-8 cm. in
length, and widening and branching towards the tip always
being dichotomous and 1-4 times branched. Sometimes giving
a ruffled appearance to the plant. The fruiting ramuli
occur on stipes and rarely on top of frond generally
appearing after the first branching division of plant,,
principally on surface, rarely marginal. Gigartina
papillata J. Ag. is difficult to distinguish from the red
brown sandstone on which it grows when exposed, as it is
a deep, pure red in color. It favors the landward surface
of rocks and has been taken at White Point, Arch Beach,
and La Jolla, but is apparently lacking at the other
stations. One point of interest lies in the close
resemblance of Gigartina papillata to similar forms collected
at Pismo Beach, Cambria Pines, and Monterey to the north of
the subtropical area. The periodicity of Gigartina
papillata seems to follow that of Gigartina eatoniana,
but would be interesting to follow because of its location
54
in the high tidal zone and the conspicuous proliferations
which would he easy to distinguish. Further study would
probably reveal this as a variety of one of the related
species.
An interesting species endemica'lly is Gigartina
serrata Gardner, which may be found in the lower littoral
zone during low tide at Balboa Palisades, in large
quantities. This has also been called Gigartina
canaliculata f. laxa, though the collection made at the
above point was identified by Dr. Gardner. This plant is
similar to Gigartina canaliculata except for its size and
the larger coarser more conspicuous fruiting ramifications.
It has been described by Dr. Gardner from specimens
taken from San Diego to Ensenada.^* Gigartina serrata was
collected at Balboa Palisades in 1908 and is not noted in
any of the reports of surveys since nor in collections to
1932. This species is not to be found north of this
locality and is lacking at Laguna. One specimen was taken
in September 1933 at La Jolla, but the survey of that
vicinity cannot be considered complete, although it was
not common in areas in which collections were made at La
Jolla proper and at a point two miles south of that city.
^ N. L. Gardner, 'New Rhodophyceae on the Pacific
Coast of North America III "(Uhiv, of OaixfT'Puo T in Boh,'
Vol. 13. l\fo. 16. 1927). p. 334-.
55
Some of the species of Gigartina as listed by
Setchell and Gardner were not found during the collecting
periods from 1931-1934. Of these several are of interest.
Gigartina echinata Gardner described by Dr. Gardner'*' has
been reported from La Jolla but is commonly to be collected
at Santa Catalina and Santa Cruz. Gigartina farlowiana
J. Ag* has been found from Monterey to La Jolla. The type
specimens on file at the University of California are
somewhat fragmentary and the plant could easily be confused
with related, forms. Gigartina asperifolia J. Ag. is
similar in many respects to Gigartina eatoniana and
Gigartina spinosa the plants in the collections studied
being questioned bj Setchell and Gardner, the distribution
is in southern California from Santa Barbara to La Jolla.
Gigartina spinoaa has also been collected at San Pedro.
The decurrent spines are one of its characteristics. A
few type specimens of Gigartina corymbifera Kuetz^ are on
file from Santa Barbara though not found elsewhere in
southern California. Gigartina harveyana Kuetz, has been
previously noted in relation to Gigartina boryi; it ims
formerly known as Gigartina rnicrophylla, Harvey. Other
N. L. Gardner, Hew Rhodophyceae on'V/the Pacific
Coast of North America III (Univ. of OalTfT'PuBT in Bo't'T
W rr~ 1 3 7 f lo 7 " T 6 'T T S 2 7 7 . 335.
species v/hose location in the southern area is noted but
are doubtful as types characteristic of the species named
al?e : Gigartina papillata. J. Ag., Gigartina obove ta J. Ag.,
Gigartina cristata Setchell, Gigartina agardii isetch. et
Gard. Nov., Gigartina jardinii J. Ag.
DISCUSSION
57
The periodicity of th^ species Gigartina eatoniana
has been studied for its reproductive structures. This
is complete with two exceptions. The notation has been
previously made of the vast numbers of juvenile sterile,
one-lobed fronds appearing from December to March on the
rocks. Such plants have been collected but probably not
in sufficient numbers as they are readily lost in pressing
and filing. Also the antheridial plants still may be open
to question because of their inconspicuous fruiting pro
liferations and the difficulty to distinguish them when
dried. Specimens preserved in 4 per cent formalin were not
numerous enough to tabulate. Undoubtedly further research
in this line will be essential.
The two species . Gigartina leptorynchos and Gigartina
canaliculata with their annotation of fifty specimens each
provide data for comparative study, but'the antheridial
plants here are still open to question, particularly for
Gigartina canaliculata. This feature of the genus
Gigartina seems to be a common difficulty for, as
1 p
previously mentioned Gardner and Sjodsedt^ both describe
^ N. L. Gardner, New Rhodophyceae from the Pacific
Coast of North America IlT”(Univ. ’ of Calif, rub'.’ "in Bot. "
Vo 1r "137 No"; I67~IS2T7. p. 334.
2
L. G. Sjodsedt, Floridian Studies (Lund. 1926).
58
various species but the antheridial plants are incomplete
in these considerations of the other species which they
describe.
Former studies of the genus in southern California
are limited to the distribution in the floris tic and geo-
botanical studies of Mr. Heil and Miss Parks. Miss Parks
further noted the occurrence in the spring of carpospores
in Gigartina horrida, now Gigartina leptorynchos and
Gigartina spinosa, now Gigartina eatoniana.^ She also
noted that Gigartina canaliculata shows .a marked increase
in mass and growth between February and May,
It Is probable that a longer period for study with
the same check of plants, temperature and water salinity
would show a distinct rhythmic variation in their life
cycles. The Gigartinas being perennial present a far
more complex problem than that of the red algae studied by
p
Lewis at 'Goods Hole or the DIctyota which he observed at
1'Taples. These plants were both studied to learn more
about their seasonal changes and periodicity, but they show
little to compare with the same feature, i, e. periodicity,
In perennial algae.
^ E. II. Parks, A Geo-Botanical Survey of Selected
Groups of Marine Algae on"" the Coast of ""Southern (JaTif or hi a
(U.' S . C . THesTs* ' l h ' 3 ' 2 ’ ). pp. 04-85.
q
I. F. Lewis, The Seasonal Life Cycle of Some of
the Red Algae at '.'oods Hole ('Plant ‘ Tor I ’ d’ 7 Vo I ,T7. Mo.*"!?.
W I o T _
SULinAKY
The study of species of the genus Gigartina has
been made with reference to periodicity. Material has
been collected over a period of' two years from
June 1932 to July 1934,
1. The periodicity of the species Gigartina
eatoniana, Gigartina leptorynchos, and Gigartina
canaliculata with relation to their location was made in
southern California, This showed a complete life cycle
of cystocarpic, tetrasporic, sterile and antheridial
plants for the former species.
2. An outline of_the history of the genus
Gigartina on the Pacific coast shows that, the specimens
collected during some of the early explorations were
described in algal literature by Lamoroux (1809),
C. Agardh (1824), Greenville (1830), J. G, Agardh (1842),
Olsen (1898), Humphry (1901), giving us some idea of the
existence and structure of species found, the subject has
recently been extended by the work on classification by
Setchell and Gardner and on. morphology by Sjodsedt and
\
Kylin.
3. The significance of the study 'of periodicity is
noted in relation to the probable commercial value of the
genus and as an interesting problem. To harvest plants at
a time to avoid the extermination of the species, their re
productive periods must be known.
60
4. The area studied has been described and
classified as to its zoning showing the associations in
relation to: (a) tides, current, (b) rock formation, and
(c) geographical distribution.
5. The various species of Gigartina to be found at
different stations and in various zones were listed,
6. The method of collection was described with
regard to preservation and notation of specimens in respect
to forms taken in each monthly period.
7. The method of microscopic and superficial study
are noted with efforts to embed and stain sections.
8. Special observations were made on the species
Gigartina eatoniana, Gigartina leptorynchos and Gigartina
canaliculata with regard to the classification of each
plant as to periodicity in the occurrance of antheridia,
tetraspores or sterility,
9.. »General observations of interest were made in
relation to individual species as to regeneration,
development and associations.
10* Other species of Gigartina to be collected in
the southern California region were gathered and listed to
show the extent of this genus, and to give an idea as to
its importance.
11, plates, graphs, tables, gig\ire3, drawings and
photographs are submitted to supplement written descriptions*
ACKNOWLEDGEMENT S
During the process of investigations the author
was indebted to several persons for their assistance.
Dr# Johnstone advised methods used in filing and
charting specimens and aided in establishing a systema
tization of the work accomplished*
Dr* Gardner of the University of California very
kindly checked and verified the identification of species
of the specimens gathered from June 1932 to the summer
of 1933, and further denoted several antheridial
specimens#
Mrs# Glare of the University of Southern California
made various suggestions and comments during the latter
part of the work#
Acknowledgements are also made for the valuable
assistance of my committee; Dr# G# E# Johnstone, chair
man; Dr# H# de Forest; and Dr. Clements#
LITERATURE CITED
Agardh, J. G.
1848-76 - Species Genera et Ordines Algarum, Lund
Vol. a, 'Ft. '1, p. T '2Y0-2'8'3
" 2, Pt. 2, p. 354, 426
” 2, Pt. 3, p. 723-840
" 3, Pt. 1, p. 410-426
Anderson, C. L.
1891 - List of California Marine Algae with
Rotes, Zoe
VoT.’ 2, pp 217-225
Chamberlain, C. J.
1932 - Methods in Plant Histology, Univ. of
Chicago* Press p. 247-251
Clarke, L. L.
1865 - Common Sea ’.beds, Fred. Y/arne Co., London
"pp* T04',T05T
Couch, E. B.
1915 - Ecology of the Marine Algae of Point Firmin
The sis, H5e pt7 B'ioi. U. ' S . ' " ‘ C . pp.' 1-63
Far low, V7. G.
1882 - The Marine Algae of New England, U. S. Comm
' " ‘ of Fish “ and "Fisheries, Fart FTl Gov’t
Printing Office, pp. 148-159
Gardner,-N. L.
1927 - The Rhodophyceae from the Pacific Coast of
iTo'rth 'America,' TlT^ Dhiv. oT Calif. "Pub'.
Bo’ i . ' Vol. 13, No. 16. pp. 333-336
Harvey, H. W.
1928 - Biological Chemistry and Physics of Sea
hater, Macmillan C o , "Hev/""YorF
Harvey, W. H*.
1856 - Lectures on Marine Algae, Smithsonian
Tris'ti'tute, V i as'Kirig'ton' ""D. C.
Heil, W. G.
• 1932 - Marine Algae of the Santa Monica Bay Region
Thes'fs7 'B'o't,H3epiV U. " 'S'TT. pp. "1-58
Hoydt, W. D.
1920 - Marine Algae of Beaufort N. C. and Adjacent
TTegions, Bui. Bureau I'lslierles,’ oT. XXAVl,
TSTT^IFIS Doc. 886
Howe, 11.
1914
Humphrey,
1901
Johnson, :
York, H. !
1915
Kylin, H.
1925
Lawrence,
1898
Lewi s, I.
1910
Olsen, I v l .
1899
Oltmanns,
1922
Parks, E.
- 1932
Setchell,
1917
y
63
- The Marine Algae of Peru, Torrey Bot.
~UXuT 5 " , ’ "’ "Y"6X, XV. pp. 94-129
H. B.
- Observations on Gigartina Exasperata,
'rfarv"tlihn. Hot.' stud..' Vol. ‘ 2. pp.' 601-
608
S.
i .
E,
P.
E.
- Relation of Plants to Tide Levels,
Carnegie Institute, 17ashing'ton 13* 0,
Pub, No. 206, p. 160
Marine Red Algae in the Vicinity/of Friday
Hart) or, V/ as hing ton, Lund- • pp. 28, 2V
- Marine Algae of Los Angeles County, Vol. I,
II. ColTe‘ c‘ t ‘ 1 on
- The Seasonal Life Cycle of Some Red Algae
aFl?'oo"ar^s" "Holey The’ TTanT”'orTS Vol.'“ITT”
“Io7~2--------
— Observations of Gigartina, Minn. Bot.
: jj5q— ------ -
Freiclrich
- Morphologie und Biologie Der Algen, II
k '~BmilI'-T5p7''ll7X^8'X71J4T,“ 4T2t:4^U---
III Band pp. 2, 60, 182, 210, 273, 338,
342, Jena
M.
- A Geo-Botanical Survey of Selected Groups
of Marine " ’ Algae on the "(Toast of Southern
TJalii-orhia 1 'From Ananeim Landing to 'Laguna
Beach'. ' "Thesis, U'. . " Dept. df“HotX
W • A«
- Geographical Distribution of Marine Algae,'
Science, Vol." ” 15,' pp.' i'97^04'7 llarth 2, "
1917
64
Setchell, W. A.
1920 The Temperature Interval in the
GeographTcal"’ 0fat'ri" 15uti'on of Marine Algae,
'ScienceVol* 52, August 77, 'TQ'SO.' pp*
187-90
Setchell, VJ. A.
Gardner, H. L.
1902-03
Setchell, W. A.
Gardner, H. L.
1933
Sjodsedt, L. G.
1926
Tilden, J', E.
1933
Transeau, E. N,
1916
Tressler, D. K.
1927
Yates, L. G.
1901
Marine Algae of North 'Western America,
univ. dfCalTT , ”Fu5T i'n""Bot‘ ' . " VoT.‘ T7
pp. 165-418
A preliminary Survey of Gigartina, With
Special Reference to Tts pacific North
An i e ’ ri'can"' Species , * Univ , of Calif . " ” Tu5T
in ¥ot; Vol. ' 77, No. 10. pp, 255-340
B'loridian Studies, Lund
Classification of Algae Based on
Evolutionary1 "Levelopment with' Special
Reference ’ ’ to’ Pigrrientatlon,” B’ ot’ I ’ Gazette
Vol.' 95. pp. 59-77
Periodicity in Fresh Water Algae,
Amer "Jour.' Botl "3';""121-133
The Wealth of the Sea, The Century Co.,
N. Y. pp. BTJ-TUO
Marine Algae of Santa Barbara County,
C a If f dr ni" a,” ~Bui 1. Ho. 7 T , S'ant a 'Bar bar a
Soc of "If at' 1. Hist. pp. 3-2 0
65
r ' i j i l T P 1 •
GIGART1WA P ATOM ANA
Pig. 1. Cystocarpic plant
Pig. 2, .Antheridial plant
Pig. 3. Tetrasporic plant
Pig. 4. Sterile plant

67
PLATE II.
GIGARTINA LEPTORYKCHOS
Fig* 1. Cystoearpic plant
Pig. 2. Tetrasporic plant
Pig. 3. Sterile plant
68
PLATE III.
01 GARTHS A G A1IALICUL AT A
Pig. 1, Cystocarpic plant
Pig. 2. Tetrasporie,.plant
Pig, 3. Sterile plant
70
■"TmrrjPn'Tfiijrr'nF
71
PLATE IV.
CYSTOCARPIC STRUCTURE OF GIGARTIKA SATONIANA
Fig. 1. Cross section of mature cystoesrp, x 100.
S'ig. 2. Long section of a mature cystocarp, x 50.
Fig. 3. Ripe carpospores, x 430.
Fig. 4. Cystocarpic proliferationa, x 10 from
fresh material.
a. Group of two cystocarps,
b. Group of three cystocarps.

73
Fig. 1
Fig. 2
Pig. 3
Fig. 4
FLATS V.
TETRASPORIC STRUCTURES OH Gl&AETIHA
SATOHIAHA
. A portion of the tetrasporic frond showing
proliferations, x 1, from fresh material
. R'ature tetrasporic mass, x 430.
. Tetrasporic proliferations, x 18,
mature tetraspores, x 430.
74
75
PLATE VI.
AX'IThI)5iILlAL STRUCTURED ON GIGA:-.TINA EATONIAHA
Pi]g. 1. Portion of a plant bearing antheridia,
x 250- •
Fig. 2. Tip of a fresh plant, x 1.
Fig. 3. Antheridia, x 430.
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Asset Metadata

Creator Hervey, Josephine (author)

Core Title A comparative study of certain species of gigartina with reference to their periodicity

Degree Master of Science

Degree Program Botany

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag biology, botany,OAI-PMH Harvest

Language English

Contributor Digitized by ProQuest (provenance)

Advisor Johnstone, George R. (committee chair), [illegible] (committee member), Clements, Thomas (committee member)

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c17-781965

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