Monstera luteynii Madison, Contr. Gray Herb.

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

30. Monstera luteynii Madison, Contr. Gray Herb. 207: 89. 1977. ( Fig. 52 )

Type: — COSTA RICA. Alajuela: along road to and around the edge of Laguna Hule, NE of Cerro Congo, and about 8 km NW of the village of Cariblanco , 20 km N of Vara Blanca, alt. 740–900 m, June 1972, J. Luteyn 3227 (holotype MO!, isotypes US!, DUKE!) .

Nomadic vine, appressed-climbing and pendent habit. SEEDLINGS: filiform. JUVENILE PLANTS: root climbers; blades appressed to the phorophyte. ADULT PLANTS: root climbers; stems light brown, warty with pustules, cylindrical and sulcate; internodes 3–10 cm long, 1.0– 1.5 cm diam., 3.2–6.6 times longer than wide; anchor roots 2–4 cm long; feeder roots whitish and corky; petiole smooth and striated at base, 8–13 cm long, sheathed to base of the geniculum, prolonged into a free ligule 1–3 cm long; petiole sheath deciduous; geniculum striated abaxially, terete, 0.5–1.0 cm long; blades ovate to broadly elliptic, rounded to truncate, cordate or subcordate at base, acuminate at apex, coriaceous, drying yellowish or black with yellowish green, 12–16 × 9–13 cm, not decurrent on geniculum; midrib flattened adaxially, convex abaxially, primary lateral veins 4–6 per side, obscure adaxially, prominent abaxially, departing midrib at 35–50°; secondary veins prominent and reticulated towards the margin; collective veins not visible; fenestrations absent; margins entire. INFLORESCENCES on pendent stems; peduncle smooth, 3–5 cm long, 5–8 mm diam.; spathe obtuse, unknown color; spadix unknown during development, creamy-white at anthesis, 6–8 cm long, 1.7–2.0 cm diam., 1.6–3.4 times longer than wide; basal sterile flowers 3–5 mm long; fertile flowers 3–6 mm long; stamens 1–6 mm long, with laminar filaments; anthers 1–2 mm long; ovary unknown; style compressed and hexagonal, 1–2 × 3–4 mm; stigma linear or circular; berries with an olive-green stylar cap during development, mature stylar cap green; pulp white; seeds dark-brown with white dots, elongated, 4–6 mm long.

Distribution and ecology: — Monstera luteynii is endemic to Costa Rica known only from the Atlantic watershed in the Cordillera de Tilarán, Cordillera Central and the Cordillera de Talamanca at 360–900 m, in Tropical wet forest life zones.

Phenology: —Flowering has been recorded in November, and fruiting in March.

Discussion: —The species is a member of sect. Marcgraviopsis . It is known from the type locality in Cariblanco (around the Hule Lagoon), the sector of Peñas Blancas in San Carlos and the Monteverde Biological Reserve on the Quebrada Celeste in the basin of the Peñas Blancas River and Cartago in the sector of Las Vueltas. It resembles Monstera pittieri (both bloom on hanging stems), but that species has flowers somewhat separated on the spadix. Madison (1977) distinguished Monstera luteynii by having ovate leaves less than twice as long as wide, verrucate stems and petioles, whereas M. pittieri has lanceolate leaves, 2–5 times longer than broad, and smooth stems and petioles.

Additional specimens examined: — COSTA RICA. Alajuela: San Ramón, Ángeles, Remnant trees in pasture, 2 km N.E. of La Balsa de San Ramón , 900 m, 26 September 1976, (Fl.), R. Lent 3889 ( CR!, MO!) ; San Ramón, Peñas Blancas, Quebrada Celeste , Rio Penas Blancas , Campo , 900 m, 6 November 1989, (Fl.), E. Bello 1468 ( CR!) ; Cartago: Jiménez, Lurtes arbres a Las Vueltas , 635 m, 1 Enero 1898, (Fr.), A. Tonduz 12841 ( MO!) .

Figures

FIGURE 52. Monstera luteynii from San Ramon, Costa Rica. (A) Branching pendent habit. (B) Stem with entire cordate leaves. (C) Stem and base of petioles densely verrucose with light brown pustules. (D) Leaves on a hanging stem with a persistent but dry sheath and a 2 cm long ligule (arrow). (E) Densely striate and terete scaly geniculum. M. Cedeño et al. 1672 (USJ). Image from Cedeño-Fonseca et al. (2022).