EVANS—THE NORTH AMERICAN SPECIES OF ASTERELLA. 281 
Asterella californica Underw. Bot. Gaz. 20: 60, 1895. 
Cievea limbata Solms; Stephani, Bull. Herb. Boiss. 6: 773. 1898, in part. 
Thallus green above but usually more or less pigmented with purple along 
the margin and on the ventral surface, mostly 1.5 to 2 em, long and 7 to 10 
mm. wide (rarely only 4 to 7 mm.), plane when moist, more or less incurved 
when dry, with undulate margins, branching by forking, the keel broad and 
rounded; epidermis composed of cells with thin walls, sometimes showing 
minute trigones, averaging about 50 X 30 u; pores slightly elevated, measuring 
(with their surrounding cells) mostly 110 to 130 » in length and 100 to 120 uw 
in width, surrounded by 6 (sometimes 7 or 8) series of cells with 3 cells in each 
series, the radiating walls more or less thickened, the cells containing oil bodies 
as in A, tenella; green tissue rather loose, the air chambers in 4 or 5 layers in 
the median portion, those of the dorsal layer higher and larger than the others 
but somewhat subdivided by supplementary vertical partitions often reaching 
nearly or quite to the epidermis; compact tissue occupying from one-fourth to 
one-third the thickness of the thallus in the median portion, thinning out gradu- 
ally on the sides and extending about halfway to the margin, composed of cells 
with thin unpitted walls, an ocensional larger cell both here and in the green 
tissue containing slime; myccrhiza rarely present in the ventral portion; 
ventral scales large and imbricate, extcnding beyond the margin, ovate to lunu- 
late, deeply pigmented throughout or with hyaline appendages, the margin irreg- 
ularly sinuate or toothed; cells containing oil bodies mostly 10 to 15, scat- 
tered: appendages mostly 2 to 4, variable in shape but usually narrewly subu- 
late and acuminate from a broad triangular base, mostly 0.6 to 0.9 mm, long 
(including the basal portion) and 0.08 to 0.15 mm. wide, sometimes with a 
sharp tooth or lobe but usually entire, the cells in apical portion mostly 35 to 
60 » long and 25 to 35 » wide; inflorescence dioicous; antheridia forming an 
elongated median patch, sometimes forked, at some distance from the apex; 
ostioles low; a few paleae sometimes present; peduncle straw-colored, some- 
times with brownish or purplish pigmentation, naked or nearly so, 1 to 3 cm. 
high; disk of receptacle green, about 5 mn). across, low-hemispherical, deeply 
lobed, almost smooth, the lobes mostly 4 (sometimes 5), extending obliquely 
outward, the margins and the almost bipartite involucre entire or vaguely 
and irregularly crenate or dentate; pseudoperianth white or rarely purplish, 
mostly 12 to 16-cleft, the divisions lanceolate, connate at the apex; capsule 
circumscissile at the middle or above by an irregular line, the operculum break- 
ing up into fragments; spores yellow, mostly 100 to 120 uw in diameter, with 
wavy wings 12 to 20 » wide along the edges, the surface covered over more or 
less completely with a fine and often irregular reticulum with meshes 8 to 4 uw 
across, formed by delicate, slightly raised lines, the spherical face showing in 
addition 4 or 5 broad and rounded, irregular ridges lower than the wings, 
anastomosing but not forming a reticulum, the plane faces with 1 or 2 similar 
ridges; elaters yellow, variously curved, mostly 240 to 450 » long and 12 to 
16 » wide, tapering slightly toward the blunt ends, the median portion with 
1 or 2 spirals, the ends with 1. 
Growing on banks or among rocks; locally abundant in California; known 
also from Arizona and Guadalupe Island. The following specimens have been 
examined: 
Arizona: Bright Angel Trail, bottom of Grand Canyon, 1913, Nichols (Y.; 
listed by the writer, somewhat doubtfully, in Bryologist 20: 61. 1917). 
CALIFORNIA: Without definite locality or date, Bolander, Bigelow (C., N. Y., 
Y.; distributed by Austin, as Fimbriaria californica, in Hep. Bor. Amer., no. 
185); Oak Run, Shasta County, Baker & Nutting (N. Y.); Ukiah and Half 
Way House, Mendocino County, Howe (N. Y.); Murphy, Calaveras County,. 
