3. ERYTHROPHYLLASTRUM Plate 4 .

Erythrophyllastrum Zand., gen. nov. Type: Erythrophyllastrum andinum (Sull.) Zand. Holotype: Peru, Andes, U.S. Expl. Exp. Wilkes, 1838–1842, FH.

Plantae magnae, usque altitudine 3.5 cm; caules in sectione interdum triangulares, filo centrali robusto praediti, hyalodermidem e stratis 1–3 texturae laxae compositam in maturitate subcollapsam evolventes; folia in statu madido late patentia, late lanceolata, longitudine 3.5–4.5 mm, marginibus planis, integris, uni- vel bistratosis, apice acuto, base subvaginanti, lamina superna in solutione KOH rubrescenti, costa in sectione semicirculari strata stereidarum duo evolventi praedita.

Plants forming cushions, green to reddish brown above, reddish brown below. Stems branching irregularly, to 3.5 cm in length, transverse section rounded-pentagonal, central strand strong, sclerodermis weakly developed, substereid, hyalodermis of 1(–3) cell layers of lax cells, often not collapsed; axillary hairs long, to 20 cells in length, basal 1–4 cells yellowish; radiculose below. Leaves appressed-incurved and curled when dry, widely spreading when moist, lanceolate, 2–3 mm in length, upper lamina broadly channeled to keeled, broadly grooved along costa, margins plane, entire, upper lamina unistratose or variably bistratose in large patches or throughout; apex acute; base broadly sheathing below, with weak shoulders; costa percurrent, with lamina inserted laterally, superficial cells quadrate, papillose, often short-rectangular near apex ventrally, dorsally usually quadrate near apex, rectangular below, 10–16 rows of cells across costa ventrally at midleaf, costal transverse section semicircular, stereid bands two and strong, the dorsal semi-circular in shape, ventral and dorsal epidermises present, the dorsal medially weak, guide cells (4–)6 in 1 layer, hydroid strand(s) very weak, often multiple; upper laminal cells small, subquadrate, 7–10 µm in width, 1:1, walls thin to evenly thickened, superficially weakly convex on both sides of lamina; papillae bifid, 2–3 per lumen to multiplex, generally hollow, crowded; basal cells differentiated across the sheathing base, rectangular, ca. 13 µm in width, mostly 3–4:1, walls thin. Propagula not seen. Dioicous. Perichaetia terminal, inner leaves lanceolate, somewhat larger than the cauline, to 4.5 mm in length, sheathing the seta in lower 1/3, lower cells rectangular, walls weakly porose. Perigonia terminal, weakly gemmate. Seta ca. 1 cm in length, 1 per perichaetium, reddish brown, twisted clockwise; theca 1.5–2.0 mm in length, reddish brown, cylindrical, exothecial cells short-rectangular, ca. 2:1, thin-walled, stomates at base of capsule, phaneropore, annulus of 1–2 rows of vesiculose cells; peristome teeth rudimentary, consisting of a few low plates, to 30–45 µm in height. Operculum long-rostrate, oblique, ca. 1.2 mm in length, cells straight. Calyptra conic-cucullate, smooth, ca. 1.5 mm in length. Spores ca. 13 µm in diameter, light brown, weakly papillose. Laminal KOH color reaction red.

A monotypic genus found in the Andes of Colombia and Peru, on moist rock at high elevations (ca. 3700–4000 msm).

This taxon was previously placed with Erythrophyllopsis (Zander 1977a), which is superficially similar by its red coloration; stem with large central strand; leaves with plane margins, broad, flat costae and sheathing leaf bases; and upper lamina bistratose. Erythrophyllastrum differs from Erythrophyllopsis by the former's 1(–3) layers of stem hyaloderm cells (Pl. 4, f. 2), comprising loose tissue little collapsed with maturity; stems sometimes triangular in section; the leaves commonly shorter and more broadly lanceolate, sometimes reflexed above the base and widely spreading to squarrose; the leaf base less strongly sheathing, sometimes without highly differentiated “shoulders” (Pl. 4, f. 4); upper laminal cells variably entirely bistratose or bistratose in patches or entirely unistratose (Pl. 4, f. 7–8); both costal section and dorsal stereid band semicircular or nearly so (Pl. 4, f. 7–8, both being reniform in Erythrophyllopsis); dorsal costal cells usually quadrate near the leaf apex; and peristome even more reduced, to a few small plates (Pl. 4, f. 12).

Through its plane, reflexed, broadly keeled leaves with sometimes weakly sheathing base, small, dense upper laminal cells, and basal cells usually differentiated completely across the leaf, Erythrophyllastrum may have much the general aspect of species of Barbula sect. Convolutae (e.g. B. amplexifolia).

Number of accepted species: 1.

Species examined: E. andinum (BUF).

New combination: Erythrophyllastrum andinum (Sull.) Zand., comb. nov. (Trichostomum andinum Sull., U.S. Expl. Exp. Wilkes Musci 5, 1859; Erythrophyllopsis andina (Sull.) Zand.).