Plants reddish black, black or greenish brown. Leaves curved or secund to straight, wide-spreading to squarrose, short-lanceolate, widest proximally, apex oblique or symmetric; costa absent; leaf margins entire; basal laminal cells short- to long-rectangular, marginal cells rounded-quadrate to short-rectangular, walls sometimes thickened, usually pitted, straight; medial laminal cells quadrate to short-rectangular, 1-stratose or occasionally 2-stratose in patches, lumens rounded, rectangular or irregularly stellate; laminal papillae usually present, commonly large, whitish. Sexual condition cladautoicous or autoicous; perichaetial leaves differentiated, convolute-sheathing. Spores 20-32(-50) µm.
Andreaea rupestris Hedw., Sp. Musc. Frond. 47. 1801.
Syntypes. Sweden, England, "Bructeri" and Germany, sin. coll.Plants small to medium sized, 1–3 cm high. Leaves frequently with a whitish bloom, 1–2 mm long, crowded, spreading to appressed when dry, ovate- to oblong-lanceolate, weakly constricted and panduriform above the base, concave; apices acute to bluntly acute; margins thick, erect, entire (perichaetial leaves shortly and bluntly dentate); ecostate; upper median cells 15–19 µm × 10 µm, short-rectangular, upper marginal cells quadrate, median cells distinctly longer than the marginal cells, strongly incrassate, and porose throughout, the upper cells with stellate lumina commonly with large, thick papillae on the dorsal surface (occasionally on ventral), basal cells 50–75 µm × 10 µm, long rectangular. Sporophytes not seen in Central America.
3. Andreaea rupestris Hedw. 岩生黑藓 yan-sheng hei xian Spec. Musc. Frond. 47. 1801. Syntypes. Sweden: "Bructeri," sin. coll.; England, "Annaemontani," sin. coll. Andreaea petrophila Ehrh. ex Fuernr, Flora 10 (Beibl. 2): 30. 1827. Plants blackish green to black, or reddish brown to dark brown, up to 2 cm high in dense tufts. Stems erect or ascending, simple or sparsely branched. Leaves 0.70–0.76 mm × 0.30–0.36 mm, imbricate, appressed when dry, lanceolate from an ovate base to ovate-panduriform to panduriform, with acute to obtuse apex; margins entire, sometimes crenulate above in reference to the mammillae present on laminal cells, slightly incurved; upper laminal cells irregularly quadrate, rounded-rhomboid to short-rectangular, 8–16 µm × 4–8 µm, irregularly thick-walled, papillose to nearly smooth; basal cells elongate to narrowly rectangular, 20–60 µm × 2–6 µm, with strongly and irregularly thickened walls, pitted. Autoicous or dioicous. Perichaetial leaves oblong-lingulate, obtuse to acuminate, about 1.5–2.0 mm long. Pseudopodium 1.5–2.0 mm long. Capsules exserted, ovate-oblong, blackish brown, split to 4 values from near the base to the apex when mature. Spores red-brown, 20–28 µm in diameter, densely papillose. 3a. Andreaea rupestris ssp. rupestris 岩生黑藓原亚种 yan-sheng hei xian yuan-ya-zhong Andreaea likiangensis Chen, Acta Phytotax. Sin. 7(2): 103. 1958. Type. China: Yunnan, Li-jiang Co., W.-S. Hsu 335a (holotype PE). Plants are autoicous, usually blackish green to black, sometimes reddish black. Leaves are lanceolate from an ovate base. Papillae of laminal cells sometimes are not distinct. Andreaea rupestris ssp. rupestris is different from A. rupestris ssp. fauriei by having ovate to ovate-lanceolate leaves and by its autoicous sexual condition. Plants of A. rupestris ssp. rupestris are often blackish, while those of A. rupestris ssp. fauriei are often reddish.
In Southern Africa, A. rupestris is identified by its generally red-brown colour, ecostate leaves and frequently papillose leaf cells. The plants tend to vary in size and leaf shape, but specimens are rarely difficult to identify. A broader interpretation of A. rupestris would undoubtedly encompass many of the ecostate species of Andreaea on the sub-Antarctic Islands.
Plants small, forming cushions, red-brown to black-green; saxicolous. Stems 5-20 mm high, irregularly branched; in section round, central strand absent, inner cortical cells in 2-3 rows, corners thickened, outer cells in 2 rows, smaller, round, incrassate. Leaves appressed or with spreading apices dry, erect-spreading wet; ovate to oblong-lanceolate, occasionally constricted above base, 0.3-1.5 mm long; apex weakly cucullate, acute to obtuse; margins entire, incurved; lamina in section unistratose. Costa absent. Upper laminal cells quadrate, incrassate, frequently with strongly thickened corners, smooth to strongly papillose on dorsal surface; basal cells linear to rectangular, irregularly thickened; basal marginal cells short-rectangular to quadrate. Autoicous. Perichaetia terminal; leaves elliptical, 2 mm long; apex obtuse. Pseudopodia 1-2 mm long, pale green; capsule just exserted, elliptical, to 1 mm long, dark red-brown; dehiscence slits extending from mid-capsule to near apex; spores round, 20-25 µm, yellow, weakly papillose.
Plants small, red-brown, forming cushions. Stems 5-20 mm long, irregularly branched. Leaves ovate to oblong-lanceolate; apex acute to obtuse; margins entire, incurved; costa absent. Upper laminal cells quadrate, incrassate, smooth to strongly papillose; basal cells linear to rectangular. Capsule just exserted, pseudopodia 1-2 mm long. Spores weakly papillose. A. rupestris is most easily identified by its red-brown colour, ecostate leaves and frequently papillose leaf cells.
Very widespread in distribution, A. rupestris is also the most commonly collected Andreaea in Southern Africa. This species is known from mountains of the southwestern, central and eastern Cape and the Drakensberg of Lesotho, Natal and the Orange Free State.