MONSTERA OREOPHILA
PROTOLOGUE: Monstera oreophila Madison, published in Contributions from the Gray Herbarium of Harvard University 207: 54 (1977).
DISTRIBUTION: Costa Rica to Panama: Costa Rica, Panama.
DISTRIBUTION NOTE: Panama: Chiriquí iNaturalist: Chiriquí, Heredia, Puntarenas, San José.
SPECIES DESCRIPTION:
Robust nomadic vine, with appressed-climbing habit. Seedlings: bearing foliage leaves. Juvenile plants; root climbers; stems light or dark green, smooth or rough; internodes 2–8 cm long, 3–6 mm diam.; petiole distinct, light or dark green, smooth or warty, 7–15 cm long, sheathed to base of the geniculum; petiole sheath persistent or deciduous; blades lanceolate, ovate, subcordate to rounded at base, acuminate at apex, 8–16 × 3–11 cm, not appressed to the phorophyte; fenestrations present or absent. Adult plants: root climbers; stems dark or light green, smooth or warty, cylindrical; internodes 1–5 cm long, 2–4 cm diam., 0.5–1.2 times as long as wide; anchor roots black, feeder roots, suberose; cataphylls light-green, warty or smooth, deciduous; petiole dark or light-green, smooth or distinctly warty, 25–70 cm long, sheathed to base of the geniculum; petiole sheath deciduous with fibrous residues; geniculum smooth, sulcate adaxially, convex abaxially, 2–5 cm long; blades ovate to lance-ovate or oblong, asymmetrically cuneate to rounded or subcordate at base, short to long-acuminate at apex, subcoriaceous, drying yellowish, brownish, or very dark brown to almost black, 25–75 × 20–35 cm, 1.3–2.0 times longer than wide, decurrent on the geniculum, decurrent portions 0.5–2.0 mm wide; midrib sulcate adaxially, convex and smooth to markedly warty abaxially, drying blackish or yellowish; primary lateral veins 11–45 per side, departing midrib at 75–90°, rarely forked, sunken adaxially, prominent abaxially, drying blackish or yellowish; secondary veins parallel but becoming reticulated toward the margin; collective veins not visible; fenestrations present (rarely absent), the ones located along each side of the midrib small and roundish, the ones located farther from the midrib much larger and elongated; margins entire or pinnatilobed due to tearing of the fenestrations that extend to the margin, 3–7 lobes per side, the sinuses reaching halfway or all the way to the midrib, 0.5–6.0 cm wide.⁴
INFLORESCENCE:
Inflorescences produced on ascending stems, 1–5 per synflorescence, with or without subtending cataphylls; peduncle smooth or warty, 13–40 cm long; spathe acuminate to long-acuminate, glaucous-green externally during development, glaucous-green or pinkish externally and light orange-yellow internally at anthesis, becoming torn at base and hanging (reflexed) from the midrib base during the staminate phase of anthesis, deciduous soon after anthesis, 10–16 × 8–11 cm, up to 6 cm longer than the spadix; spadix white during development, yellow at anthesis, 7–15 cm long, 1.3–3.0 cm diam., 4.4–5.5 times longer than wide; basal sterile flowers 4–6 mm long, with a transparent secretion; fertile flowers 5–7 mm long; stamens 1.5–7.0 mm long, with laminar filaments; anthers 1.5–3.0 mm long; ovary rectangular in longitudinal section, ribbed, 3–5 × 2.0–3.5 mm; style hexagonal, 1.5–2.0 × 2–4 mm; stigmatophore absent or present, slightly columnar; stigma linear; berries with light green to creamy-white stylar caps during development, mature stylar caps creamy-white; pulp white; seeds black, oblong, 5–7 mm long.⁴
ECOLOGY:
Monstera oreophila ranges from Costa Rica to Panama, occurring at 800–2300 m, in Tropical wet forest, Premontane wet forest, Premontane rain forest and Lower montane rain forest life zones. Flowering has been recorded in February-March, May, and October-November, and fruiting in February-April, August, October, and December.⁴
ETYMOLOGY:
From Greek oreophilus, "mountain-loving," referring to the habitat of the species.²
NOTES:
1. The species, a member of sect. Monstera, is characterized by its petiole asperous for its entire length and with deciduous wings, leaf blades fenestrate throughout and sometimes pinnatilobed, the asperous midrib, and the spathe papaya-colored externally and internally. It could be confused with the allopatric Monstersa buseyi, but that has the petioles verrucate-asperous, the leaf blade with the midrib smooth, and an externally cream-colored spathe. In Costa Rica (Central and Talamanca cordilleras), and Panama (Boquete and La Fortuna, Chiriquí Province), the populations of Monstera oreophila exhibit asperous or smooth petioles and midribs, salmon to papaya pink spathes, drying yellowish, blackish or dark brown. However, Costa Rican populations in Tilarán and Guacanaste show certain differences, such as the smooth stem, smooth green petioles with the sheath semi-persistent, smooth midribs, heavily fenestrate or pinnatilobed leaf blades, the spathe externally glaucous green and internally light salmon to pale rose, and the prophylls and cataphylls smooth and drying completely yellow (Cedeño-Fonseca et al. 2021a, 2022).⁴
2. Conservation status: Monstera oreophila is protected in the Refugio de Vida Silvestre Jaguarundi, Reserva Forestal Cordillera Volcánica Central, Reserva Forestal Los Santos, Zona Protectora Cerros de Escazú, Zona Protectora Cerros de La Carpintera, Zona Protectora Las Tablas, Zona Protectora Río Banano, Reserva Indígena Chirripó, Reserva Biológica Alberto Manuel Brenes, Parque Nacional Barbilla, Parque Nacional Guanacaste and Parque Internacional de La Amistad.⁵
STORY:
STORY TITLE: A spathe that tears itself open
The spathe of Monstera oreophila is glaucous green or pinkish outside and light orange-yellow within at anthesis, and during the male phase it tears at the base and hangs reflexed from the peduncle, falling soon after.⁵ Across the Central and Talamanca cordilleras and in western Panama the spathe runs from salmon to papaya pink, while the populations of Tilarán and Guanacaste have it glaucous green outside and pale salmon to rose inside, together with smooth stems and petioles and yellow-drying cataphylls.⁴
When Monstera lentii was studied in Costa Rica, inflorescences of Monstera oreophila were opened as well and beetles were recovered from its floral chambers, the only pollination observation the species has.⁶
Its fenestration pattern, one or two rows of holes with the largest reaching the margin, is otherwise found only in Monstera epipremnoides and Monstera lentii of the same mountains, and, far to the south, in Monstera kikiae of the Colombian Chocó.⁷
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera oreophila Madison
2. Contributions from the Gray Herbarium of Harvard University 207: 54 (1977) — protologue.
3. iNaturalist: Monstera oreophila
Additional photos from iNaturalist by katiebr, Maks Syratt, Marcel Esquivel, Dario Taraborelli, Mery Joe, Carlos G Velazco-Macias, Florian Bachmann, Jake Rehage, jeanjacquesgodon, Laura Palmieri, Luke Berg, Mabelin, Michael Butler, ogockman, Alejandro Juarez, Daniel Garrigues, dmehlman, Leonardo Álvarez-Alcázar and Petr Kocarek