Download PDF

152
ZYGNEMATACEAE
6. Spirogyra condensata (Vaucher) Kiitzing 1843. Phycologia
Generalis, p. 279.
Vegetative cells 45-^)0/1 x 45-1 20 m, with plane end walls; i chro-
matophore, making .5 to 4 turns; conjugation scalariform and lateral;
tubes formed by both gametangia; fertile cells cylindric or slightly
enlarged; zygospores ellipsoid, 34-3^/^ x 50-75 ju; median spore wall
yellow, smooth. (PI. XXI, Fig. 11.)
United States: Wisconsin and Kentucky; eastward to Massachusetts
and New Jersey,
Widely distributed in Europe; reported from South America.
Characterized by its short cells and closely spiraled chromatophores.
Sterile cells sometimes inflated.
7. Spirogyra variformis Transeau 1938. Amer. Jour. Bot. 25,
pp. 526-27.
Vegetative cells 43-50M x (70-) 108-140 (-200) m with plane end
walls; I chromatophore, making 2 to 5 turns in the cell; conjugation
scalariform; tubes formed by both gametangia and widest at the mid-
dle; some sterile cells inflated to 72-ioo/t; fertile cells mostly cylindric
but sometimes enlarged or inflated; zygospores ellipsoid or ovoid,
45-54 /x X 58-90 M, rarely spherical, 52-60 /u. in diameter; median wall
brown, smooth. (PI. XXI, Figs. 9-10.)
Africa, Cape Town (Stephens Coll.).
8. Spirogyra gracilis (Hassall) Kiitzing 1849. Species Algarum,
p. 438.
Vegetative cells 16-24/x x 50-ioo/x, with plane end walls; i chromatophore,
making .5 to 4 turns; conjugation scalariform; tubes formed
by both gametangia; fertile cells inflated, mostly on the conjugating
side; zygospores ellipsoid with rounded ends, 23-30 ju. x 40-65 i^^; median
spore wall yellow-brown, smooth. (PI. XXI, Fig. 5.)
chusetts.
United States: Colorado; Texas; Missouri; Michigan; Ohio; Massa-
Widely distributed in Europe; reported also from China and Siam.
9. Spirogyra fragilis Jao 1935. Sinensia. 6, p. 590, PI. 6, Fig. 64.
Vegetative cells 24-29 jt^ x 54-160/11, with plane end walls; chromatophore
I (rarely 2), making 1.5-6 turns; conjugation scalariform; tubes
formed by both gametangia; fertile cells slightly inflated, usually a Uttlc
more on the conjugating side; the female gametangia often separate
from each other after conjugation; zygospores ellipsoid with more or
less rounded ends, 22-38 /li x 36-67/1; median spore wall yellow, smooth.
(PI. XXI, Fig. 6.)
United States: Texas, Johnson City, April 24, 1938 (Taft Coll.).