N o sto c e llip so sp o rn itt. (Desm.) Rabh. Alg. Eur. ii., 169.
Plant terrestrial. Frond plane, applied to the ground by the
lower surface, gelatinous, rufous brown.
Trichomes densely interwoven, pale æruginous green, joints
cylindrically elongated, loosely connected, sheaths broad, homogenous.
Heterooysts elongated, elliptical, spores oblong,
smooth.
S iz e . Joints -004 mm., heterooysts -006--007 mm., spores
•006 X -006--008 X •OlO mm.
Born. & Thuret Notes Alg. ii., 94, t. xxvii., fig. 7-11.
Hormosiphon ellipsosporum, Desm. PI. Crypt. No. 133.
On the ground amongst moss.
Plate XC. fig. 8. Triohome of Nostoc ellipsosporum producing spores
X 400 ; fig. 9, portion of triohome which at one extremity exhibits the
sheath ; fig. 10, trichome with the greater part of the joints transformed
into spores : fig. 11, young trichome from germinating spore. Figs. 9,
10, 11, X 600 diam. after Bornet.
I I I . H dmifosa. Species terrestrial. Fronds at first globose,
then confluent, and forming gelatinous patches adhering by their
lower face. Spores smooth.
N o s to c m u s c o rum . Ay . Disp. Alg. p. 55.
Frond dark green, foliaceous, tuberculate, opaque.
Trichomes diffused, irregularly interwoven, pale æruginous
green. Sheaths confluent. Heterooysts sphærioal, usually
intercalated. Spores oval.
S iz e . Joints -0035 mm., heterocysts -005 mm., spores -006
X -01 mm.
Born. & Thuret Notes Alg. p. 96, t. 27. Rabh. Alg. Eur. ii.,
173. Eng. Fl. V . , 399. Hass. Alg. 292, t. 74, f . 4. Gray
Arr. i., 351.
On calcareous rocks, and the mosses th at cover them.
Plate XC. fig. 12. Nostoc muscorum nat. size; fig. 13, trichome X
400; fig. 14, sterile trichome ; fig, 15, fructifying trichome; fig. 17,
triohome with spores involved in sheath ; figs. 17,18, spores germinating ;
figs. 14-18, X 600, after Bornet.
N o s to c h um ifu s um . Cann. Eng. El. ii., 399.
Frond small, at first globose or subglobose, from tbe size of
a peppercorn, olive, then brownish, shining opaque when dry.
Trichomes olive, slender, vertically folded, sheaths well defined.
Heterocysts globose. Spores oval.
S iz e . Jo in ts -0022 mm., heterocysts -003 mm., spores -004
X -006 mm.
Harv. Man. p. 184. Born. & Thuret Notes Alg. p. 99.
Nostoc parietinum, Rabh. Alg. Eur. ii., 178.
Anabaena granularis, Kutz. Tab. Phyc. i., t. 94, f. 6 .
Nostoc granulare, Rabh. Alg. Eur. ii., 163.
Nostoc tepidariorum, Braun, in Rabh. Alg. No. 2461, 2462.
On mosses and on walls in greenhouses, &c.
Plate XCI. fig. 1. Nostoc humifusum, nat. size; fig. 2, triohome x
400 ; fig. 3, portion of trichome x GOO.
IV . C o m m u n i a . Species terrestrial. Fronds at fir s t globose,
then tongue-shaped, plane or irregular.
N o s to c c om m u n e . Vauch. Conf. p. 222, t. 1 6 ,/. 1.
Adult frond sub-orbicular, folded, undulating, entire or lobed,
often perforated, olive, yellowish-brown, or becoming brownish.
Trichomes flexuous, loosely interwoven, pale blue-green.
Joints sphærical, compressed, uniform. Heterooysts globose.
S iz e . Joints, -0045--006 (usually -005) mm., heterocysts
•007 mm.
Rabh. Alg. Eu r. ii., 175. Hass. Alg. t. 74, f. 2. Borzi.
Alghe Fioo. p. 284. Eng. Bot. i., t. 2556, pi. p. 1625. Eng.
Bot. i., t. 461. Eelh. Cant. 441. Lightf. Fl. Scot. 898. P u rt.
Midi. Fl. ii., 612. Abbot. Bedf. 271. W ith . Arr. iv., 80.
Jenner Fl. Tnnb. Wells, 190. Harv. Man. 183. Johnst.
Fl. Berw. ii., 262. Grev. Fl. Edin. 822. Mack. Hib. 245.
Flor. Dev. ii., 49. E n g . Fl. v., 898. Dickie Bot. Guide, 310.
Tremella nostoc, Linn. sp.
Nostoc ciniflonum. Born. & Thuret Notes Alg. ii., 102.
Nostoc foliaceum, Ag. Svst. Alg. p. 19. Hass. Alg. t. 76,
f. 2. Rabh. Alg. Eur. ii., 173. Eng. F l. v., 899. Harv. Man.
188. Mao. Hib. 245. Dickie Bot. Guide, 310.
Nostoc arctum, Kutz. Tab. Phyc. ii., t. 7, f. 1.
Nostoc littorale, Kutz. Tab. Phyo. ii., t. 8, f. 1.
Nostoc prismaticum, Ces. in Rabh. Alg. Eur. ii., 169.
Nostoc rugosum, Kutz. Tab. Phyc. ii., t. 11, f. 1.
Nostoc salsuni, Kutz. Tab. Phyc. ii., t. 8 , f. S.
On wet ground.
Plate XCI. fig. 4. Nostoc commune, nat. size ; fig. 5 trichome x 400 ;
fig. 6, portions of trichome x 600, fig. 7, portion of trichome.
V. Sphærioa. Fronds globose or subglobose (becoming irregular
ivhen they grow large) , limited by a firm and resisting peridermic
coating.
N o s to c sp h æ ric um . Vauch. Conf. 223, t. 16, / . 2.
Fronds firm, sphærical, about the size of a pea, gregarious,
olive or bluish-green, or brownish, with a firm brownish or
colourless periderm.
I I