Aschisma
Utkast Eur. Bladmoss., 28. 1878 ,.
| Taxon | Illustrator ⠉ | |
|---|---|---|
 | Aschisma kansanum | Patricia M. Eckel |
Plants small, gregarious or forming a thin mat, green. Stems ca. 0.2 mm, branching seldom; rounded-pentagonal in transverse-section, hyalodermis absent, sclerodermis absent, central strand present, weak; rhizoids absent; axillary hairs ca. 3 cells in length, basal-cell thick-walled. Leaves incurved, tubulose when dry, weakly spreading when moist; oblong or triangular to short-lanceolate, often falcate or concave, adaxial surface broadly channeled, 0.6–1 mm; base little differentiated in shape; distal margins plane to recurved, entire to sharply serrulate beyond mid leaf, bordered beyond middle, proximally or throughout by 1–3 rows weakly papillose, elongate cells; apex broadly or rounded-acute, costa excurrent as a sharp mucro, occasionally rough or denticulate, adaxial outgrowths absent, adaxial cells elongate, in 2-4 rows, transverse-section circular, adaxial epidermis absent, adaxial stereid band present, substereid, guide cells 2–4 in 1 layer, hydroid strand absent or present, abaxial stereid band present, often substereid, elliptical in section, abaxial epidermis absent; basal-cells strongly differentiated, rising higher along margins in a V, rectangular, little wider than distal cells, 3–5: 1, walls of basal-cells very thin to evenly thickened; distal medial cells quadrate to occasionally shortrectangular, 9–12 µm wide, 1: 1 (–2), papillae stout, 2-fid, crowded, scattered or centered over lumens, cell-walls evenly thickened, flat or bulging only ventrally or on both exposed surfaces. Specialized asexual reproduction absent. Sexual condition monoicous (paroicous or stalked autoicous bud at base of perichaetial plant); perichaetia terminal, interior leaves not sheathing, long-elliptic, to 1.5 mm. Seta hyaline, very short, ca. 50 µm, straight. Capsule yellowish-brown, spheric, about 0.3 mm, with a small blunt apiculus of ca. 30 µm, annulus absent; operculum absent; peristome teeth absent. Calyptra short-triangular, split once or twice, 0.2–0.3 mm, rough. Spores 18–24 µm, essentially smooth to spiculose-papillose, yellowish-brown. KOH laminal color reaction yellow.
Discussion
Species 2 (1 in the flora).
Aschisma is widely distributed in the Mediterranean area, and is disjunctive to central North America. It is found in dry climates on soil.