Monstera maderaverde Grayum & Karney, Economic Botany, 2012

Croat, Thomas B., Cedeño-Fonseca, Marco & Ortiz, Orlando O., 2024, Revision of Monstera (Araceae: Monsteroideae) of Central America, Phytotaxa 656 (1), pp. 1-197 : 111-113

31. Monstera maderaverde Grayum & Karney, Economic Botany 66(2): 209–211, f. 3–5. 2012.

Type: — HONDURAS. Atlántida: Mazapita Cloud Forest, Cordillera Nombre de Dios. ca. 7.2 km (direct point to point distance) SSE of Mesapita, on ridge forming the divide between Río Mazapa and Río Mezapita, 1160 m, 7 Nov. 2010, A. Karney s.n. (holotype MO-6240501–02 !) .

Nomadic vine, appressed-climbing and pendent habit. SEEDLINGS: bearing foliose leaves. JUVENILE PLANTS: root climbers; blades apparently not appressed to the phorophyte; fenestrations absent. ADULT PLANTS: root climbers; stems green; internodes 12.5–17.5 cm long, 0.7–1.0 cm diam., 17.5–18.0 times longer than wide; petiole smooth, 12.5–17.5 cm long, sheathed 4–6 cm before base of the geniculum; petiole sheath marcescent to deciduous; unsheathed portion terete; geniculum 0.5–0.8 cm long; blades ovate to suborbicular, truncate to cordulate at base, short-acuminate at apex, coriaceous, 12.8–16.0 × 8.0– 14.6 cm, drying blackish, slightly shorter to slightly longer than petiole; midrib ribbed adaxially, prominent abaxially; primary lateral veins 2–4 per side, poorly defined per side, departing midrib at 35–50°; secondary veins parallel (or reticulated towards the margin); margins entire; perforations absent or occasionally present (at least 1.5 cm in diam.). INFLORESCENCES on pendent, erect stems; peduncle terete, smooth, 9–13 cm long, 0.3 cm diam.; spathe obtuse to mucronate, light green during development, yellow suffused with green tint externally and white internally at anthesis, completely open at apex, 4–6 × 4–5 cm, as long as the spadix; spadix unknown during development, white suffused with a yellow tint at anthesis, 4.8–7.8 cm long, 1.6–2.2 cm diam.; basal sterile flowers slender towards base; fertile flowers 4–7 mm long; anthers 1 mm long; ovary 3–4 × 2–3 mm; style hexagonal; stigma linear; berries with a greenish stylar cap during development, mature stylar cap yellowish at base and dark green towards base; pulp white; seeds unknown.

Distribution and ecology: — Monstera maderaverde is endemic to Honduras, known only from the type locality in the Cordillera Nombre de Dios, at 1160 m, in cloud forest in a Premontane wet forest life zone.

Phenology: —Flowering in November.

Discussion: —The species, a member of sect. Tornelia , is characterized by it hemiepiphytic, somewhat scandent habit, slender stems with a somewhat flaking epidermis, long-petiolate leaves, slender inconspicuously sheathed petioles, broadly ovate, weakly veined, acuminate, dark gray-brown-drying blades which are broadly rounded at base with weak venation, and long-pedunculate inflorescence with a narrowly obovate spadix.

Monstera maderaverde could be confused with the Costa Rican endemic M. luteynii , with which it shares leathery leaf-blades of similar size and shape ( Karney & Grayum 2012). But it differs because M. luteynii belongs to the sect. Marcgraviopsis Madison with juvenile plants with shingle-forming leaves, adult with pendulous stem habit, shorter petioles (8–13 cm long), and larger spadices (6–8 × 1.7–2.0 cm) on shorter peduncles (3–5 cm long). ( Karney & Grayum 2012).

Additional specimens examined: — HONDURAS. Atlántida: Mezapita Cloud Forest, Cordillera Nombre de Dios. Ca. 7.2 km SSE of Mezapita (as the crow flies), on ridge forming the divide between the basins of the Ríos Mezapa and Mezapita , 15°30’39”N 087°19’41”W, 1160 m, 07 November 2010, Alexander P. Karney s.n. ( MO!) ; Yoro: Yoro. Camino Real de San José Texíguat a Campo Nuevo en un lugar llamado Las Letras al oeste del Cerro Cabeza de Negro, 15°28’00”N 087°26’05”W, 1010 m, 24 abril 1995, Reinaldo Aguilar & Randall J. Evans 4076 ( COL, CUVC, MEXU, MO, PMA, US) .