Synopsis of the species of Cheilolejeunea (Marchantiophyta, Lejeuneaceae) in the Pacific dominion and Páramo province of tropical America Author Gil-Novoa, Jorge Enrique Programa de Pós-graduação em Botânica, Escola Nacional de Botânica Tropical, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro. Rua Pacheco Leão, Horto, 2040, 22460 - 080, Rio de Janeiro-RJ, Brazil. & Grupo Sistemática Biológica, Herbario UPTC, Universidad Pedagógica y Tecnológica de Colombia, Tunja, Boyacá, Colombia. Author Costa, Denise Pinheiro 0000-0001-9495-3029 Instituto de Pesquisas Jardim Botânico do Rio de Janeiro - IPJBRJ, Rua Pacheco Leão 915, 22460 - 030, Rio de Janeiro, RJ, Brazil. denisepinheirodacosta @ gmail. com; https: // orcid. org / 0000 - 0001 - 9495 - 3029 denisepinheirodacosta@gmail.com text Phytotaxa 2023 2023-03-14 587 2 73 120 http://dx.doi.org/10.11646/phytotaxa.587.2.1 journal article 10.11646/phytotaxa.587.2.1 1179-3163 7731813 2.1. Cheilolejeunea adnata (Lehmann) Grolle (1977: 529) var. adnata — Jungermannia adnata Lehmann (1834: 46) . Type:— CUBA . In caduce Oreodoxae regiae, Pöppig s.n. (W, lectotype designated by Grolle 1977 ).— Fig. 2I–M . Plants yellowish green to light brown, 0.6–0.9 mm wide. Stems in cross section 60–100 µm in diameter, 7–8 epidermal cells, 16–28 × 10–14 µm; 9–10 medullary cells, 9–16 × 5–11 µm. Ventral merophytes 2 cells wide. Leaves subimbricate to imbricate, generally orbicular to ovate, fully flat, 415–500 × 350–500 µm; margin entire; apex broadly rounded; cells orbicular to ovate, cuticle smooth, inconspicuous trigones; basal cells 22–27 × 15–21 µm, median cells 18–29 × 16–20 µm, marginal cells 11–16 × 9–11 µm. Lobules rectangular to ovate, 1/4 leaf length, free margin involute, tooth acute, formed by a cell long, straight to slightly curved, 10 × 25 µm, keel arched. Underleaves distant, orbicular, 1.5–2.5 x wider than the stem, 150–210 × 80–160 µm, bifid to 1/3–1/2, with a V-shaped sinus, margin entire, base cuneate. Dioicous. Androecia on branches, with 5 pairs of bracts. Gynoecia on branches, with a lejeuneoid innovation (sometimes absent), bracteoles obovate, 620 × 390 µm, bifid to 1/8. Perianth 3-keeled, the keels weak, beak short. Vegetative reproduction by means of caducous leaves with hyaline rhizoids on the margin. Distribution and habitat :—Neotropical, occurring in the Caribbean islands, Costa Rica , Panamá , Colombia , Venezuela , Ecuador ( Gradstein 2020 , 2021), Guyana , Suriname , and Brazil ( Bastos 2017 ). In the study area, generally grows epiphytic on tree trunks and shrubs, below 2000 m , in the lowland rainforest and lower montane rainforest, in the Puntarenas-Chiriquí, Guatuso-Talamanca, Trinidad , Magdalena, Cauca, Chocó-Darién, and Venezuelan provinces of Pacific dominion ( Fig. 3 ). Notes :—The species is easily distinguished by the presence of deciduous leaves with rhizoids on their margin, lobules ca. 1/4 of the length of the leaf, with a prominent tooth, and distant underleaves, slightly wider than the stem, orbicular, with cuneate bases. Specimens examined :— BRAZIL . Acre : Alto Juruá , 8°56’11”S , 72°33’50”W , 28 November 2000 , Costa 3904 ( RB ) . Pernambuco : Recife , Dois Irm „os, 50 m , 3 August 1998 , Costa 3366 ( RB ). COLOMBIA . Amazonas : Comunidad “ Peña Roja ”, 0°34’S , 72°08’W , 200 m , 14 July 2000 , Idárraga , 2477 ( HUA ) . Antioquia : Tarazá , 7°33’35.37”N , 75°24’59,41”W , 199 m , February 2017 , Buitrago 609439 ( COL ) . Cauca : Guapi , Isla Gorgona , 20 m , 11 November 1987 , Aguirre-C. 6747 ( COL ) . COSTA RICA : Guanacaste . Liberia , National Park Rincon de la Vieja , Trockenwald , 750-800 m , 1 Juary 2000, Schäfer-Verwimp & Holz SV /H-0405 ( ALCB ) . PANAMÁ . Barro Colorado : Barro Colorado Island , 120 m , Salazar-A. 15142 ( QCA ) . SURINAME . Nickerie : 5°N , 57°W , 150 m , Bekker 1355a ( PMA ) .