Download PDF

150
ZYGNEMATACEAE
186. With 6 to 8 chromatopliores in
each cell, spores ellipsoid 85. 5. wrightiana
186. With 5 chromatophores in each
cell, spores lenticular \(£. S. azygospora
Aplanospores have been found together with zygospores in some
collections of the following species: S. catenaeform is, S. denticiilata,
S. farlowii, S. gratiana, S. groenlandica, S. hyalina, S. inflata, S. juer-
gensii, S. rnajuscula, S. neglecta, S. obovata, S. parvula, S. pratensis,
S. protecta, S. quadrata, S. qiiinquelatninata, S. reftexa, S. sahnii,
S. semiornata, S. spreeiana, S. sitbpapidata, S. tenuissima, S. tjibodensis,
S. varians, S. weberi.
Descriptions of Species
SPECIES WITH PLANE END WALLS
USUALLY ONE CHROMATOPHORE
1. SpmoGYRA COMMUNIS (Hassall) Kiitzing 1849. Species Algarum,
p. 439. Hassall. 1844. History of British Freshwater
Algae, p. 148, PI. 28, Figs. 5-6.
Vegetative cells i8-26iu, x ^5-90 m with plane end walls; i chro-
matophore, making 1.5 to 4 turns; conjugation scalariform and lateral;
tubes formed by both gametangia; fertile cells cyUndric, rarely enlarged;
zygospores ellipsoid, 19-26 m x 36-78 /a; median spore wall yellow,
smooth. (PI. XXI, Fig. i.)
Jersey.
United States: Colorado to Texas; east to Massachusetts and New
Reported from all the continents, also New Caledonia.
Distinguished from other species with similar vegetative cells and with
approximately the same dimensions by the smooth ellipsoid spores, the
cylindric fertile cells, and the absence of inflated sterile cells. Found hybridizing
with S. varians at Charleston, Illinois. The resulting segregates were
also present.
2. Spirogyra intorta Jao 1935. Sinensia. 6, p. 590, PI. 5, Fig. 58.
Vegetative cells 25-29 /j. x 60-1 /x,
83 with plane end walls; filaments
generally curved to spiral; i chromatophore, making 3.5-6 turns in the
cell; conjugation scalariform and lateral; tubes formed by both gam-
etangia; fertile cells cylindric, sometimes slightly enlarged; zygospores
ellipsoid, with pointed ends, 22-29/i x 4i-68;ti; median spore wall
yellow, smooth. (PI. XXI, Fig. 2.)
United States: Texas, Johnson City, April 24, 1938 (Taft Coll.).
China, Szechwan.