The Taxonomy of Polysiphonia in Hawaii 1 
Ernani G. Menez 2 
ABSTRACT: An investigation of Polysiphonia collections from Oahu, Hawaii, 
Molokai, and Maui of the Hawaiian Islands has revealed the presence of seven 
species: Polysiphonia mollis Hook. & Harv., Polysiphonia pulvinata (Roth) J. Ag., 
Polysiphonia subtilissima Mont., Polysiphonia ferulacea Suhr., Polysiphonia yona- 
kuniensis Segi, Polysiphonia flabellulata Harv., and Polysiphonia rhizoidea sp. nov. 
These seven species of Polysiphonia were recognized primarily by their morpho- 
logical features. 
Some characteristics of Polysiphonia which have not been previously used by 
monographers but which appear to be important criteria for delimiting specific 
entities are discussed. One of these is the presence of more than one secondary pit 
connection between adjacent pericentral cells, a condition present in P. rhizoidea 
and P. yonakuniensis but not in the other species mentioned above. The other 
is the presence of multicellular rhizoids, a condition which was observed only in 
P. rhizoidea. Previously, authors have accepted the rhizoids of Polysiphonia as 
being unicellular. 
Although there are a number of published 
articles on the marine algae of Hawaii, none of 
them deals specifically or intensively with the 
taxonomy of Polysiphonia. Up to the present, 
only six species of Polysiphonia have been re- 
corded in the literature as occurring in Hawaii: 
Polysiphonia aquamara Abbott, Polysiphonia 
calothrix Harv., Polysiphonia ferulacea Suhr., 
Polysiphonia mollis Hook. & Harv., Polysiphonia 
polyphysa Kuetz., and Polysiphonia tongatensis 
Harv. 
With respect to the published records of these 
six species, reference may be made to the works 
of Chamberlain (1860), Falkenberg (1901), 
Tilden (1901), Lemmermann (1905), Mac- 
Caughey (1918), Yendo (1918), Weber van 
Bosse (1923), Neal (1930), and Abbott (1947). 
The objectives of the present study were to 
1 Part of a thesis submitted to the Graduate School 
of the University of Hawaii in partial fulfillment of 
the requirements for the degree of Master of Science in 
Botany, March, 1962. Manuscript received March 8, 
1963. 
2 Biology and Botany Department, University of 
British Columbia, Vancouver 8, Canada. 
evaluate the validity of these taxa and to de- 
termine if additional species of Polysiphonia are 
represented in Hawaii. The species included in 
this study were recognized primarily by morpho- 
logical features. 
ACKNOWLEDGMENTS 
The author is indebted to Dr. Maxwell S. 
Doty, of the University of Hawaii, Dr. George 
Hollenberg, of the University of Redlands, Cali- 
fornia, and Dr. Toshio Segi, of the Prefectural 
University of Mie, Japan, for their invaluable 
comments; to Dr. Benjamin Stone, of Guam 
College, for preparing the Latin description of 
Polysiphonia rhizoidea sp. nov.; to Mr. E. H. 
Bryan, Jr., and Miss M. Neal for permission to 
examine the exsicatti materials of Polysiphonia 
in the Bernice P. Bishop Museum; to Drs. 
Charles Lamoureux and Sidney Townsley, of the 
University of Hawaii, for their critical reading 
of this paper; and to the Botany Department of 
the University of Hawaii, for providing field 
and laboratory facilities and supplies for this 
research. 
207 
