Monstera wilsoniensis M. Cedeño & Grayum, Nordic J. Bot.

Croat, Thomas B., Cedeño-Fonseca, Marco & Ortiz, Orlando O., 2024, Revision of Monstera (Araceae: Monsteroideae) of Central America, Phytotaxa 656 (1), pp. 1-197 : 186

52. Monstera wilsoniensis M. Cedeño & Grayum, Nordic J. Bot. 38(12): 1–13. 2020. ( Figs. 90 , 91 ).

Type: — COSTA RICA: Puntarenas, Coto Brus, San Vito, Jardín Botánico Wilson , Reserva de bosque primario, 1353 m, 10 Oct 2018 (fr.), M. Cedeño, M. Blanco, M. Mata & O. Alvarado 1484 (holotype USJ! [two sheets], isotypes MO!, PMA!) .

Nomadic vine, pendent habit. SEEDLINGS: bearing foliage leaves. JUVENILE PLANTS: root climbers; stems light green with black pustules; internodes 3–5 cm long, 4–6 mm diam.; petiole distinct, dark or light-green, smooth, 5–10 cm long, sheathed to base of the geniculum; petiole sheath deciduous; blades ovate, lanceolate, attenuate or truncate at base, acuminate at apex, subcoriaceous, 8–15 × 2–6 cm, not appressed to the phorophyte; fenestrations absent. ADULT PLANTS: root climbers; stems light-green to dark with black pustules, cylindrical; internodes 2–10 cm long, 1.0– 1.5 cm diam., usually 3.0–6.6 times longer than wide; cataphylls light-green, deciduous but leaving dry fragments on the peduncle; anchor roots dark brown; feeder roots brown; petiole dark green, sometimes white-spotted, smooth, 13–20 cm long, sheathed to base of the geniculum; petiole sheath deciduous; geniculum smooth, sunken adaxially, convex abaxially, 1.0– 2.5 cm long; blades lanceolate or oblique, cordate, subcordate to obtuse at base, acuminate at apex, subcoriaceous, drying greenish, yellowish or blackish, 15–25 × 13–15 cm, slightly decurrent to the medial part of the geniculum; midrib ribbed adaxially, convex abaxially, drying yellowish or blackish on both surfaces; primary lateral veins 15–25 per side, forked, slightly sunken adaxially, prominent abaxially, departing midrib at 55–65°, drying yellowish or blackish; secondary veins reticulate; collective veins visible; fenestrations absent or infrequently present; margins entire. INFLORESCENCES on ascending or pendent stems, 1–3 simultaneously at flowering time, arranged in the axils of the leaves or into cataphylls; peduncle smooth, 10–15 cm long; spathe long-acuminate or mucronate, light green during development, yellowish green externally and white internally at apex, thin, completely open, deciduous after anthesis, 13–18 × 9–13 cm, up to 4 cm longer than spadix; spadix creamy during development, yellowish-cream at anthesis, 7–13 cm long, 1.5–2.0 cm diam.; basal sterile flowers 3–5 mm long, with a transparent stigmatic secretion; fertile flowers 4–6 mm long; stamens 2–6 mm long, with laminar filaments; anthers 1–2 mm long; ovary quadrangular in longitudinal section, ribbed, 3–4 × 3–4 mm; style hexagonal, 1–2 × 3–4 mm; stigma linear, with a transparent stigmatic secretion; berries with a green stylar cap during development, mature stylar cap white-cream; pulp white; seeds black, 3–5 mm long.

Distribution and ecology: —Endemic to Costa Rica on the Pacific slope of the Cordillera of Talamanca, as well as the Cerros de La Carpintera, Cerros de Escazú, and Fila Costeña, from 1200 to 2100 m, in Premontane moist forest life zones.

Phenology: —Flowering has been recorded in June and September. Fruiting in December, January and March.

Discussion: —The species is a member sect. Monstera , and differs from the other species of its genus in Costa Rica by having petioles sheathed along their entire length, petioles sheathed deciduous, leaf blades cordate at base, scarcely fenestrate, and with numerous lateral primary veins, and inflorescences on both ascending and hanging stems. This species has been confused with the lowland morphotype on the Pacific slope of M. adansonii but differs from the latter by having shorter petioles 13–20 (vs. 35–55 cm) and smaller leaf blades (15–25 × 13–15 cm, vs. 25–65 × 25–45 cm) that are cordate or subcordate to obtuse (vs. cuneate or attenuate) at base.

Monstera wilsoniensis grows mainly in Premontane moist forest life zones of the Las Cruces Biological Station and the Pacific slope of the Cordillera de Talamanca, at elevations of 1200–2100 m, while the M. adansonii morphotypes that could be confused with it grow in Tropical dry forest and Tropical moist forest at elevations of 0–900 m and have fenestrate leaf blades.

Additional specimens examined: — COSTA RICA. Cartago: La Unión, San Diego, Z.P. Cerros de La Carpintera, 1800 m, 28 September 2006, (Fr.), J. Sanchéz 1586 (CR!); Cartago, La Unión, San Diego, Z.P. La Carpintera, Ladera norte con vista a Tres Ríos, entrando por finca de los Tinoco, 1520 m, 26 March 2008, (Fr.), A. Cascante et al. 1905 (CR!); Cartago, San Nicolás, Z.P. Cerros de La Carpintera, 1689 m, 21 March 2006, (Fr.), A. Quesada 1604 (CR!); Cartago, La Unión, San Diego, Cerro La Carpintera, bosque sobre ladera hacia Tres Ríos, 1700 m, 28 February 2013, (Fr.), A. Cascate & C. Trejos 2387 (USJ!); Cartago, Cartago, San Nicolas, Cerros La Carpintera, 1700 m, 22 April 2016, (Fr.), A. Cascate & C. Trejos 2593 (USJ!); Cartago, Cartago, San Nicolas, Cerros de la Carpintera, Bosques remanentes en la parte alta, 1750 m, 3 September 2013, (Fr.), A. Cascate & C. Trejos 2409 (USJ!); Puntarenas: Coto Brus, San Vito, E.B. Las Cruces, Estación Biológica Las Cruces, Java, Reserva Forestal, 1150 m, 4 July 1994, (Fl.), W. Kress & S. Martén 94–4360 (CR!); Las Cruces, 1300 m, 11 January 1978, (Fr.), T.B. Croat 44388 (MO!); Coto Brus, San Vito, E.B. Las Cruces, Las Cruces Tropical Botanical Garden, 6 km W of San Vito de Java, Cultivated and native species, 1200 m, 6 March 1984, (Infer.), T.B. Croat 57235 (CR!, MO!); Buenos Aires, Biolley, P.I. La Amistad, Cordillera de Talamanca, area around Río Canasta, 9.5 airline km NW of Agua Caliente, between Cerro Frantzius and Cerro Pittier, Lower montane wet forest with a few pasture clearings, 1550 m, 6 September 1984, (Fr.), G. Davidse et al. 28424 (CR!, MO!); Coto Brus, San Vito, E.B. Las Cruces, Along trail between Las Cruces Botanical Garden and Río Jaba, ca. 3.5 km SE of San Vito de Coto Brus, 1180 m, 12 September 1985, (Fr.), M.H. Grayum et al. 5974 (CR!, MO!); Coto Brus, San Vito, E.B. Las Cruces, Jardín Botánico Wilson, Las Cruces, San Vito de Coto Brus, Sobre sendero Este hacia Río Java, 1100 m, 3 September 1993, (Fr.), G. Rivera 2151 (CR!); Coto Brus, San Vito, E.B. Las Cruces, Forest below Las Cruces Biological Station along trail to Rìo Java, San Vito de Java, 1275 m, 29 June 1994, (Fl.), W. Kress & W. Alverson 94–3773 (CR!); Coto Brus, San Vito, E.B. Las Cruces, Estación Biológica Las Cruces, Java, Reserva Forestal, 1275 m, 8 April 1994, (Fl., Fr.), W. Kress & J. Runk 94–4654 (USJ!); Coto Brus, Pittier, Colecta en bosque en el límite oeste de la estación, 1700 m, 2 August 2000, (Fr.), L. Acosta 2425 (CR!); Coto Brus, San Vito, Jardín Botánico Wilson, Las Cruces, Sobre sendero Este hacia Río Java, 1100 m, 30 September 1993, (Fr.), G. Rivera 2163 (CR!); San José: Pérez Zeledón, San Pedro, Las Nubes, Santa Elena, Colecta en bosque secundario y potrero, 1210 m, 4 August 1995, (Fr.), E. Alfaro 324 (CR!); San José, Dota, Copey, Providencia, Montaña fría, 1850 m, 11 October 2002, (Fr.), J. Sánchez 1344 (CR!); San José, Acosta, Sabanillas, Bajo Vanegas , por Quebrada Delicias, 1500 m, 17 December 1996, (Fr.), B.E. Hammel 20604 (CR!); San José, Pérez Zeledón, Páramo, Páramo, Providencia, Cruce sitio Pierdas, 4.7 SO de Providencia, 1854 m, 21 March 2001, (Fl.), A. Rodríguez 7276 (CR!, MO!); San José, Dota, Manglar on estero between Río Paquita and Río Viejo, 1146 m, 14 August 1936, (Fr.), C. Dodge 9825 (MO!); San José, Dota, Copey, Dota, Providencia, Zapotal, Finca propiedad de Joyce Zurcher, 1800 m, 20 August 2003, (Fr.), A. Rodríguez 8262 (CR!, MO!); San José, Pérez Zeledón, El General, Reserva Universidad de York, 1200 m, 28 November 2017, (Fr.), M. Cedeño & M. Mejía 1138 (USJ!); San José, Mora, Tabarcia, Zona Protectora Cerros de Escazú, cuenca del río Negro, 2 km en línea recta al noreste de la plaza de Palmichal en remanentes de bosque a la orilla del río, 1283 m, 19 August 2010, (Fr.), J. Sánchez & R. Chacón 2166 (CR!); San José, Alajuelita, San Antonio, Z.P. Cerros de Escazú, Alrededores de Cerro Rabo de Mico, 2200 m, 22 September 1989, (Infer.), G. Vargas & J. Sanchéz 765 (CR!); San José, Acosta, Palmichal, Z.P. Cerros de Escazú, Cuenca superior del Río Negro, Finca de señor Jericó Vindas, 1825 m, 8 July 2010, (Fl., Fr.), A. Cascante et al. 2229 (CR!); Desamparados, San Miguel, Camino rural entre pequeños fragmentos de bosque y potreros arbolados a 4.5 km E de Tobosi, siguiendo la carretera 228, 1850 m, 4 August 2015, (Fr.), A. Cascate & C. Trejos 2546 (USJ!); San José, Perez Zeledón, Páramo, Providencia, Zapotal, Bosque secundario detrás de la casa, 1805 m, 20 August 2003, (Fr.), A. Ruíz & S. Lobo 743 (CR!); San José. Aserrí. Vuelta de Jorco, Tarbaca; Bajos de Praga; b. secundario en la union de los rios Tarbaca y Cedral, 1475 m, 29 January 1994, (Fr.), J. Morales 2299 (CR!).

Figures

FIGURE 90. Monstera wilsoniensis from Coto Brus, Costa Rica. (A) Developing inflorescence. (B) Frontal (left) and back (right) views of opened inflorescence. (C) Infructescence. (D) Fertile flower in lateral view (left), and longitudinal section (right). (E) Stylar plate with stigma (left) and one stamen (right). (F) Portion of juvenile plant. (G) Portion of adult plant. (H) Sterile flower; in lateral view (left), and longitudinal section (right). M. Cedeño et al. 1484 (USJ). Image from Cedeño-Fonseca et al. (2020a).

FIGURE 91. Monstera wilsoniensis from Coto Brus, Costa Rica. (A, B) adult plants in their natural habitat. (C) Hanging stems with pendulous or sub-erect infructescences (arrow). M. Cedeño et al. 1484 (USJ). Image from Cedeño-Fonseca et al. (2020a).