Hypoglossum attenuatum N.L.Gardner

MARINE ALGAE OF THE GULF OF CALIFORNIA
Hancock-Guggenheim Expeditions of 1946
_Hypoglossum attenuatum Gardner
Locality: Puerto Libertad, Sonora
February 19, 1946
Habitat: Nos. 6SS-684 cast ashore
Nos. 685-720 from rocky reef with dominant Ishige, Colpomenta
and Cutleria. Temp. 17ř C.
Collected by E. Yale Dawson	No, 665
det. by E. Y. D.
ALGAE
DISTRIBUTED BY THE ALLAN HANCOCK FOUNDATION
THE UNIVERSITY OF SOUTHERN CALIFORNIA
eisw rem*
mOTAMlCAL
QAHD&.N
Hypoglossum attenuatum Gardner, sp.nov.
Univ.Calif.Publ.Bot.l4;l04. pl.20.f.3;pl.35-36.7 D 1927
Fronds very thin and flaccid, 3-4 cm. high,2-2.5 mm.
wide, with relatively sparse branching exclusively from
the midrib; branches abruptly attenuated at the bases and
very gradually attenuated upward, terminating in acute
apices; midrib inconspicuous, composed of two rows of
superposed cells as viewed from the flat surface, and
2-3 rows of shorter cells on either side; cells of the
monostromatic portion of the fronds slightly elongated
radially and regularly diminishing in size to the margins
of the fronds, in straight radiating rows; margins smooth;
tetrasporangia in small angular sori over the midrib at
the base of the primary branches so far as known; tetra-
spores tetrahedral; cystocarps and antheridia unknown.
Growing on Sargassum sp. libertad, Mexico, the type
and only known locality. Oollected by T.O. MacDougal,
November, 1923. Type,Herb. Univ. Oalif. no. 296658.
Of the described species of this genus, H. tenui-
folium (Harv.) J. Ag. most closely resembles this one,
judging from figures and descriptions, it may be dis-
tinguished from E. tenuifolium by its smaller size,
narrower and more attenuated fronds with fewer branches.
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