1. Cheilolejeunea acutangula (Nees) Grolle (1979: 173) .—

Jungermannia acutangula Nees (1833: 357) .

Type:— BRAZIL. Minas Gerais, in Minis Generalibus, et ad Mandioccam in Serra dos Org„os, ad terram et super muscus effusa denso caespite, Martius s.n. (STR, lectotype designated by Gradstein 2021).— Fig. 2A–H.

Cheilolejeunea choachina (Gottsche) Gradst., syn. fide Gradstein & Bastos (2021)

Plants yellowish green to light brown, 0.9–1.0 mm wide. Stems in cross section 80–100 µm in diameter, (7–)8 epidermal cells, 17–26 × 8.5–13.5 µm; (9–)11–15 medullary cells, 9–16 × 5–11 µm. Ventral merophytes 2 cells wide. Leaves subimbricate to more commonly imbricate, ovate-elongate, flat to slightly recurved at apex, 280–550 × 200–450 µm; margin entire; apex rounded to more commonly apiculate; dorsal and ventral margin curved; cells orbicular to ovate, mammillose on the dorsal side and with a low papilla (see Gradstein 2021, Gradstein & Bastos 2022), trigones usually conspicuous; basal cells 22–33 × 15–23 µm, median cells 16–26 × 13–22 µm, marginal cells 10–17 × 8–16 µm. Lobules fully inflated, ovate to rectangular, 1/3–2/5 of leaf length, free margin involute, tooth acute, formed by an elongated cell; keel arched. Underleaves usually distant to subimbricate, widely orbicular obovate, 220–300 × 200–330 µm, 2.5–3.5 × stem width, bifid to 1/4–1/3, with a V-shaped sinus, margin entire, insertion curved. Autoicous. Androecia on the main stem, or at the apex of branches, 4–6 pairs of bracts. Gynoecia with pycnolejeuneoid innovations, bracts obovate, 700 × 550 µm, apex acute. Perianth 5-keeled, the keels weak to very strong, beak short.

Distribution and habitat:—Neotropical (Mexico, Cuba, Dominica, Guadalupe, Jamaica, Panamá, Colombia, Venezuela, Ecuador, and Brazil). In general, widespread in South America (Gradstein & Bastos 2021). In the study area from 500 to 4400 m (Gradstein & Bastos 2021), in the provinces Guatuso-Talamanca, Puntarenas-Chiriquí, Guajira, Magdalena, Cauca, and Venezuelan of Pacific dominion, and Páramo province in SATZ (Fig. 3), on trunks and branches of trees and shrubs, and rocks, in savanna and deciduous forest, lowland rainforest, lower and upper montane rainforest, and grass páramos.

Notes:—The species is characterized by medium-sized plants (0.9-1 mm wide), ventral merophyte 2 cells wide, ovate-elongate leaves with mostly apiculate apices, rectangular lobules with the second tooth formed by an elongated cell, underleaves widely orbicular to obovate, distant to subimbricate, and pycnolejeuneoid innovations. The species is morphologically similar to C. lobulata, however, the lobule in the latter species is smaller (1.5–2 × stem width), and the lobule apex is obtuse (see Gradstein & Bastos 2021).

Specimens examined:— BRAZIL. Minas Gerais: Poços de Caldas, Morro S „o Domingo, 1350 m, 20 April 1991, Schäfer-Verwimp 14418 (RB). Santa Catarina: Blumenau, Parque Municipal S „o Francisco de Assis, 27°55’15”S, 49°4’30”W, 74 m, Dias 83 (RB) . Rio de Janeiro: Rio de Janeiro, Corcovado, 22°57’6”S, 43°12’42”W, 645 m, 12 April 2016, Santos 418 (RB); Parque Estadual da Chacrinha, 22°57’47”S, 43°10,57”N, 23 Mach 2016, Mauad 386 (RB). São Paulo: Cubat „o, 23°53’23”S, 46°29’51”W, 130 m, 19 October 2016, Prudêncio 180 (RB) . COLOMBIA. Magdalena: Santa Marta, Cuchilla de San Lorenzo, 11°05’40”N, 74°02’11”W, 1800 m, 17 January 1967, Winkler C123 (COL) . Santander: El Hato, Hoya Negra, 6°35’45.4”N, 73°21’28.9”W, 2203 m, 1 March 2018, Cuta-Alarcón & Gil-Novoa 424 (UPTC) . ECUADOR. El Oro: Piñas, 03°39’S, 79°44’W, 960 m, 17 March 2012, Schäfer-Verwimp 32944/ B (QCA) . PANAMA. Chiriquí: Gualaca, 1200 m, Salazar-A. 560 p. p., 525p. p. (PMA) . Colón: Portobelo, Salazar-A. 868 (PMA) .