2. ERYTHROPHYLLOPSIS Plate 3 .

Erythrophyllopsis Broth. in Herz., Biblioth. Bot. 87: 41, 1916. Type: Erythrophyllopsis boliviana Broth., Bolivia, Cerros de Malaga, Herzog 4371, syntype, M, also Tunarisee, Herzog 4765, syntype, NY.

Plants forming cushions, dark green to reddish brown above, reddish brown below. Stems branching occasionally, to 2–3 cm in length, transverse section rounded-triangular to pentagonal, central strand strong, sclerodermis weakly developed, substereid, hyalodermis of 1 layer of usually collapsed cells; axillary hairs ca. 10 cells in length, the basal 1–2 cells more firm walled or brown, otherwise hyaline; sparsely radiculose. Leaves appressed below and incurled above when dry, squarrose when moist, long-lanceolate, 3.5–4.5 mm in length, upper lamina broadly channeled to keeled, margins plane, entire, occasionally denticulate at leaf apex; apex narrowly acute; base strongly sheathing, with distinct shoulders, bordered by 4–6 rows of narrower, often thicker-walled cells; costa percurrent or ending in an apiculus, rather broad below midleaf, lamina inserted about 45°, costal superficial cells quadrate and papillose, but becoming smooth and elongate in distal 1/4 of leaf ventrally, dorsally elongate, ca. 10 rows of cells across costa ventrally at midleaf, costal transverse section reniform, stereid bands ventrally distinct, the dorsal crescent-shaped, epidermis present ventrally and dorsally, guide cells 4–6 in 1 layer, 1–3 hydroid strands usually present, weakly distinguishable; upper laminal cells bistratose across the leaf, quadrate, 7–12 µm in width, 1(–2):1(–2), walls evenly thickened, superficially weakly convex on both sides of lamina; papillae bifid, 2–6 per lumen, low, scab-like, flattened, crowded, solid or hollow; basal cells sharply differentiated nearly across the leaf base but rising highest medially, rectangular, ca. 9–12 µm (to 16 µm above) in width, mostly 4–5:1, walls thin. Dioicous. Perichaetia terminal, inner leaves little different from the cauline, sheathing the seta. Perigonia terminal, weakly gemmate, inner leaves shortly lanceolate. Seta 0.5–1.5 cm in length, 1 per perichaetium, reddish brown, twisted weakly clockwise; theca ca. 3.3 mm in length, reddish brown, cylindrical, exothecial cells rectangular, 3–5:1, ca. 13–18 µm in width, thin-walled, stomates at base of capsule, phaneropore, annulus of ca. 3–4 rows of vesiculose cells, persistent; peristome teeth much reduced or 16, truncate to shortly lanceolate, papillose, 50–130 µm in length, with up to 5 articulations, straight, basal membrane low or absent in height, papillose. Operculum conic-rostrate, ca. 1 mm in length, cells straight. Calyptra not seen. Spores 13–15 µm in diameter, light brown, essentially smooth. Laminal KOH color reaction red.

A monotypic genus of the Andes of Bolivia and Argentina, found on moist rocks at high elevations.

Erythrophyllopsis, known from one species, E. fuscula, is characterized by a combination of characters: red coloration in KOH, leaves bistratose above (Pl. 3, f. 5), with plane margins and a strongly differentiated sheathing leaf base having “shoulders” (Pl. 3, f. 3–4) at the top of the base, and peristome rudimentary or short (illustrated by Herzog 1916). It is similar to Bryoerythrophyllum by the red coloration, leaves with differentiated leaf base and upper laminal cell walls evenly thickened, with papillae crowded and bifid to multiplex. My previous treatment of this genus (Zander 1977a) included Trichostomum andinum, a morphologically similar taxon here placed in a separate genus, Erythrophyllastrum, (q.v. The upper lamina of Erythrophyllopsis, which has been figured by previous authors (Herzog 1916; Brotherus 1924–25; Hilpert 1933), is entirely bistratose. Mironia is similar but has leaves bistratose only along the upper margins, and has a well developed peristome. Leptodontium has a similarly lanceolate leaf with a broad, sheathing base, but is yellow in KOH and lacks a stem central strand, among other differences. There may be a confusion with Didymodon sect. Vineales because of the lanceolate, KOH-red leaves with dorsally quadrate costal cells; the leaf apex has ventrally elongate costal cells in a boat-shaped groove and is occasionally abruptly constricted, cf. D. occidentalis. This last taxon, however, has a quite different costa, it being dorsally rounded and protuberant, and the guide cells commonly in two layers. Hilpert (1933) placed Erythrophyllopsis in close relationship with what are here dealt with as Didymodon sect. Asteriscium, Gertrudiella and Bryoerythrophyllum.

Erythrophyllopsis challaensis is here transferred to Didymodon ((q.v.). It differs from E. fuscula in slightly larger upper laminal cells, weakly serrulate basal marginal cells, shorter and broader basal cells which are transversely slit through cell wall resorption of the medial portion of the longitudinal cell walls, and a yellow color reaction to KOH.

Number of accepted species: 1.

Species examined: E. fuscula (M, NY).

New heterotypic synonymy: Didymodon semivaginatus (Britt.) Broth. = Erythrophyllopsis fuscula (C. Müll.) Hilp.