Cheilolejeunea erostrata Schuster (1978: 427)

Gil-Novoa, Jorge Enrique & Costa, Denise Pinheiro, 2023, Synopsis of the species of Cheilolejeunea (Marchantiophyta, Lejeuneaceae) in the Pacific dominion and Páramo province of tropical America, Phytotaxa 587 (2), pp. 73-120 : 90

10. Cheilolejeunea erostrata Schuster (1978: 427) .

Type:— VENEZUELA. Tachira: Páramo de Tama, base of Pico de Banderas , 3140 m, 1 March 1976, R. M. Schuster & L. Ruíz-Terán 76-1921e (holotype F!) .

Plants yellowish green to light brown, 1–1.6 mm wide. Ventral merophytes 2 cells wide. Leaves imbricate, orbicular to ovate-elongate, recurved at the apex, 680–950 × 400–650 µm; margin entire; apex acute to more commonly apiculate; dorsal and ventral margin slightly recurved; cells orbicular to ovate, mammillose to papillose on the dorsal side, conspicuous trigones; basal cells 20–30 × 15–23 µm, median cells 16–28 × 14–22 µm, marginal cells 10–17 × 8–16 µm. Lobules rectangular, 1/3–1/2 of leaf length, free margin slightly involute, tooth very short (1 cell long), observed in few lobules; keel slightly arched. Underleaves subimbricate to commonly imbricate, widely orbicular to obovate, 450– 500 × 470–530 µm, 5 x stem width, bifid to 1/5–1/3, with a V-shaped sinus, margin entire, insertion strongly curved. Autoicous. Androecia commonly on the main stem, 3–4 pairs of orbicular bracts. Gynoecia, with pycnolejeuneoid innovations, bracts obovate, apex acute. Perianth 5-keeled, keels weak to very strong, without beak.

Distribution and habitat:—Endemic to the Venezuelan Andean páramos, on the border with Colombia; this species is only known by the type collection, growing on the branches of Scrophulariaceae shrubs, in grass páramo between 3100–3500 m, in the Páramo province ( Fig. 8 ).

Notes:—The species is characterized by the large plants with large, apparently flat and rectangular lobules (1/3– 1/2 of leaf length) but with a slightly involute free margin and very short lobule teeth (1 cell long), and perianths without a beak. More exploration is needed of the páramos between Colombia and Venezuela, to confirm the continued occurrence of the species in the area.

Taking into account its extent of occurrence and number of locations ( Hallingbäck 1998, UCN 2001), it is considered here as Critically Endangered (CR-B1a).

Figures

FIGURE 8. Distribution of Cheilolejeunea cuspidifera, C. discoidea, and C. erostrata in Pacific dominion and Páramo province.