The North American Species of Asterella (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 Excerpt: ...to one-third the thickness of the thallus in the median portion, thinning out gradually on the sides and extending about halfway to the margin, composed of cells with thin unpitted walls, an occasional larger cell bot'a here and in the green tissue containing slime; mycuvhiza rarely present in the ventral portion; ventral scales large and imbrnato, extending beyond the margin, ovate to lunulate, deeply pigmented throughout-u with hyaline appendages, the margin irregularly sinuate or toothed; cells containing oil bodies mostly 10 to 15, scattered; appendages mostly 2 to 4, variable in shape but usually narrowly subulate 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 n long and 25 to 35 n 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, sometimes with brownish or purplish pigmentation, naked or nearly so, 1 to 3 cm. high; disk of receptacle green, about 5 mm. 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 l: .ne, the operculum breaking up into fragments; spores yellow, mostly 100 to 120 n in diameter, with wavy wings 12 to 20 ju wide along the edges, the surface covered over more or less completely...