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 9. Cheilolejeunea discoidea (Lehm. & Lindenb.) Kachroo & Schuster (1961: 509) .— Jungermannia discoidea Lehm. & Lindenb. ( in Lehmann 1834: 47 ). Type :— ST. VINCENT : Ad truncus arborum, L. Guilding s.n. (not seen).— Fig. 7J–P . Plants yellowish green to light brown, 0.4–0.7 mm wide. Stems in cross section 45–52 µm in diameter, 7(–8) epidermal cells, 13–29 × 86–16 µm; 8-9 medullary cells, 6–20 × 4–9 µm. Ventral merophytes 2 cells wide. Leaves suberect to obliquely spreading, ovate-orbicular, flat, 280–3100 × 215–250 µm, margin entire; cells orbicular, subquadrate to hexagonal, without trigones or inconspicuous; basal cells 16–30 × 10–18 µm, median cells 16–24 × 9–20 µm, marginal cells 9–23 × 8–13 µm. Lobules ovate to rectangular, 130–160 µm × 95–1100 µm, free margin involute, apical tooth with 1 cell, blunt. Underleaves distant, ovate, 85–105 × 90–100 µm, 1.5–2.0 × stem width, bifid to 1/4–1/3, with a V-shaped sinus, margin entire, insertion curved. Autoicous. Androecia terminal on main stem or branches, with 3–12 pairs of bracts. Gynoecia with 1–2 lejeuneoid innovations. Perianth pyriform, 5-keeled, keels more strongly developed to apex, beak short. Vegetative reproduction unknown. Distribution and habitat :—Neotropical, occurring in Costa Rica , Panamá , Brazil , St. Vincent ( Bastos 2017 , Schäfer-Verwimp 2014); recorded here as new to Perú and Colombia . Found growing as an epiphyte on tree trunks in the study area in lowland rainforests, from sea level to 600 m , in the Guatuso-Talamanca, Puntarenas-Chiriquí, and Sabana provinces of the Pacific dominion ( Fig. 8 ). Notes :—Morphologically C. discoidea is very similar to small morphotypes of C. rigidula , the latter differing by plants more robust,>700 µm wide (vs 490–700 µm wide in C. discoidea ), underleaves 2–3 × stem width (not 0.9–2.0×), and dioicous sexual condition (not autoicous). Specimens examined :— BRAZIL . Pará : Capit „o Poço, 1°46’S , 47°4’W , 40 m , 24 June 2006 , Tavares, 950 ( RB ). Rio de Janeiro : Carapebus, PARNA Jurubatiba, 22°17’702”S, 41°40’33”W , 4 April 2006 , Imbassahy 121 ( RB ); Itatiaia , Parque Nacional de Itatiaia , 2400 m , 13 April 2000 , Costa 3843 ( RB ) . COLOMBIA . Guaviare : San José del Guaviare , 2°34’16.0’’ N , 72°53’09.7’’ W , 252 m , 4 December 2021 , Gil-Novoa & Costa 3654 ( UPTC ) . COSTA RICA : Guanacaste . Liberia , National Park Rincón de la Vieja , 750–800 m , 1 January 2000 , Schäfer-Verwimp & Holz SV /H-0392 (ALCB) . PERU . Loreto : Iquitos , Maynas , 7 August 1984 , Timme 4709 ( NY ) .