EVANS—THE NORTH AMERICAN SPECIES OF ASTERELLA. 291 
Fimbriaria elegans y cubensis Gottsch., Lind. & Nees, Syn. Hep. 565, 1846. 
Asterella elegans Trevis. Rend. Ist. Lombardo II. 7: 785. 1874. 
Hypenantron elegans Trevis. Mem, Ist. Lombardo III. 4: 441, 1877. 
Asterella cubensis Underw. Bot. Gaz. 20: 63. 1895. 
Asterella austint Underw. op. cit. 64. 1895. 
Asterella wrightii Underw. loc. cit. 
Fimbriaria wrightit Stephani, Bull. Herb. Boiss. 7: 97. 1899. 
Fimbriaria austini Stephani, op. cit. 203. 1899. 
Thailus green above, usually more or less pigmented with purple on the 
ventral surface and along the margin, sometimes with scattered dots or 
splotches of purple on the upper surface, mostly 1 to 8 cm, long and 2 to 4 
mm. wide (rarely up to 6 mm.), plane or slightly concave, with undulate and 
often crispate margins, often scarious when old and scarcely or not at all in- 
curved when dry, rarely branching by forking, usually by means of apical in- 
novations and ventral outgrowths, the keel broad and rounded; epidermis com- 
posed of cells with slightly thickened walls and sometimes with minute tri- 
gones, averaging about 50 X 30 »; pores distinctly elevated, measuring (with 
their surrounding cells) mostly 100 to 130 w in length and 70 to 100 yw in 
width, surrounded by 6 to 8 (rarely only 5) radiating series of cells with 3 or 
4 cells in each series, the radial walls slightly thickened; cells containing oil 
bodies scattered and few in the epidermis, otherwise as in A. tenella; green 
tissue compact, the air chambers mostly in 2 to 4 layers in the median portion, 
those of the deeper layers small, those of the dorsal layer higher and larger 
but subdivided by crowded vertical supplementary partitions failing to reach 
the epidermis in the vicinity of the pores; compact tissue occupying nearly or 
quite two-thirds the thickness of the thallus in the median portion, thinning 
out more or less abruptly on the sides and extending from one-third to one- 
half the distance to the margin, composed of cells with more or less thickened 
and distinctly pitted walls; mycorhiza often abundant in the lower part; 
ventral scales ovate to lunulate, usually with purple pigmentation, the cells con- 
taining oil bodies mostly 6 to 15, scattered, tending to be more numerous in 
the acropetal portion; appendages usually borne singly but not infrequently 
in pairs, narrowly lanceolate or subulate, slightly or not at all constricted at 
the base, mostly 0.6 to 0.9 mm. long (rarely down to 0.35 mm.) and 0.09 to 
0.15 mm. wide, the margin entire or vaguely crenulate from projecting cells, 
rarely bearing a single spinelike or cilium-like tooth near the base, the apex 
acuminate, the cells mostly 100 to 120 w long and 30 to 40 » wide; inflorescence 
autoicous; male inflorescence in the form of a clearly defined and _ slightly 
raised oval to emarginate disk, containing usually 15 to 30 antheridia and 
surrounded by a fringe of narrow paleae, terminal on a short or more or less 
elongated branch but sometimes with an apical innovotion; ostioles distinctly 
elevated; female inflorescence borne on a similar branch; peduncle more or 
less pigmented with purple, bearing scattered lanceolate paleae along its entire 
length (at least when young) and a denser cluster at the apex, mostly 1 to 
1.5 em, high; disk of receptacle green or somewhat purple, mostly 3 to 4 mm. 
across, coarsely tuberculate, hemispherical in the center, normally 4-lobed, 
the lobes short but distinct, extending obliquely downward and outward, the 
margins crenate, the involucre rather broad, entire or sinuate, scarcely or not 
at all bilobed; pseudoperianth usually white to brownish but sometimes more 
cr less purple, usually 8 but sometimes 9 or 10- (rarely 12) cleft, the divisions 
lanceolate, coherent at the apex; capsule brown, circumscissile above the middle 
by an irregular line, the operculum coming off in one piece; spores pale to dark 
brown, mostly 80 to 100 u» in diameter (rarely as low as 60 » or as high as 120 
