MONSTERA STANDLEYANA
PROTOLOGUE: Monstera standleyana G.S.Bunting, published in Baileya 14: 133 (1967). The protologue is reproduced below.
DISTRIBUTION: SE. Nicaragua to NW. Colombia: Colombia, Costa Rica, Nicaragua, Panama.
DISTRIBUTION NOTE: Colombia: Chocó Panama: Veraguas iNaturalist: Alajuela, Cartago, Limón.
SPECIES DESCRIPTION:
Robust nomadic vine, appressed-climbing habit. Seedlings: bearing foliage leaves. Juvenile plants: root climbers; stems light to dark green, sometimes white-dotted, smooth, cylindrical; internodes 2–6 cm long, 3–5 mm diam.; petiole distinct, dark green, smooth, 7–15 cm long, sheathed to base of the geniculum; petiole sheath persistent; blades lanceolate, subcordate to truncate at base, acuminate at apex, coriaceous, 6–15 × 4–10 cm, not appressed to the phorophyte; fenestrations absent. Adult plants: root climbers; stems dark green or beige, smooth, cylindrical; internodes 1–3 cm long, 1–5 cm diam., 0.6–1.0 times as long as wide; anchor roots dark-brown; feeder roots brown, corky; petiole light or dark-green, smooth, 20–80 cm long, sheathed to base of the blade, less frequent to base of the geniculum or to 1.5 cm before it; petiole sheath persistent with finely wavy margins; geniculum smooth, sunken adaxially, convex abaxially, 2.5–3.5 cm long; blades lanceolate-ovate to lanceolate, cuneate to rounded or truncate at base, obtuse to short-acuminate at apex, coriaceous, drying yellowish green with black dots or blackish with white dots on both surfaces, 30–80 × 10–40 cm, 1.9–2.1 times longer than wide, not decurrent on the geniculum; midrib ribbed adaxially, convex abaxially, drying black or yellowish on both surfaces; primary lateral veins 12–25 per side, strongly sunken adaxially, prominent abaxially, departing midrib at 45–65°, drying yellowish; secondary veins parallel and prominent, reticulate towards the margin; collective veins not visible; fenestrations rarely present; margins entire, rarely pinnatilobed, 3–6 lobes per side.⁴
INFLORESCENCE:
Inflorescences on ascending stems, 1 or 2 simultaneously at flowering time, arranged in the axils of the leaves; peduncle smooth, 10–35 cm long; spathe acuminate to long-acuminate, yellowish green externally during development, creamy yellow with brown dots externally and cream internally at anthesis, persistent after anthesis, light brown when dry, 10–17 × 8–12 cm, up to 5 cm longer than the spadix; spadix white during development, creamy-yellow at anthesis, 9–20 cm long, 3.5–5.5 cm diam., 5.4–6.8 times longer than wide; basal sterile flowers 4–6 mm long, with a rusty-red stigmatic secretion; fertile flowers 5–9 mm long; stamens 2–8 mm long, with laminar filaments; anthers 1.5–2.0 mm long; ovary rectangular in longitudinal section, ribbed, 5–7 × 3–4 mm; style hexagonal, 3–4 × 3–4 mm; stigmatophore columnar, 0.5–1.0 mm long; stigma circular, with a rusty-red stigmatic secretion; berries with a green stylar cap during development (covered by cream spathe), mature stylar cap moss-green; pulp gray; seed brown with dark dots, oblong, 6–9 mm long.⁴
ECOLOGY:
Monstera standleyana ranges from southeastern Nicaragua, along the Caribbean slope and near the Continental Divide to Central Panama (Veraguas, Panama) and Colombia (Chocó), at 0–1500 m, in Tropical moist forest life zones. Flowering from April to June, August, September and October. Fruiting in January, March, October and December.⁴
ETYMOLOGY:
Named in honor of Paul Carpenter Standley (1884–1963), the American botanist and author of the Flora of Costa Rica; Bunting described the species from a plant that had flowered in the conservatory at Cornell University and cited Standley and Valerio collections from Cartago and Guanacaste as paratypes.⁶
NOTES:
1. The species is member of sect. Monstera. It is distinguished from the other species in the genus by the dark green petioles sheathing throughout their entire length, with persistent and slightly wavy wings, entire leaf blade usually without fenestrations, externally yellow, coriaceous and marcescent spathe, enveloping the spadix, and the moss green infructescence. It is similar to Monstera juliusii, but the latter is distinguished by its fenestrate, sometimes pinnatilobed leaves (but see below), the externally yellowish green spathe, cream-coloured infructescence, and its distribution on both sides of the Cordillera de Talamanca, at elevations of 1800–2200 m. Monstera standleyana has been confused with the South American species Monstera lechleriana in the revision of the genus by Madison (1977). Monstera standleyana is a common species in lowland moist forests on the Caribbean slope. Adult plants of this species are variable in size, and can become very robust (with leaves up to 160 cm in length). Individuals of this species have been observed in the Gandoca-Manzanillo Mixed Wildlife Refuge (Southern Caribbean slope), with both entire and fenestrate leaves, but have never been observed in the reproductive state (Cedeño-Fonseca et al. 2022).⁴
2. Conservation status: Monstera standleyana is protected in the Estación Biológica La Selva, Reserva Indígena Chirripó, Zona Protectora Arenal-Monteverde, Reserva Biológica Alberto Manuel Brenes, Reserva de Vida Silvestre Barra del Colorado, Parque Nacional Braulio Carrillo and Parque Internacional de La Amistad.⁵
STORY:
STORY TITLE: Confused in every direction
Monstera standleyana was described in 1967 from a plant that had flowered in the conservatory at Cornell University, with Standley and Valerio collections from Cartago and Guanacaste cited as paratypes.² Ten years later the revision of the genus treated it as the South American Monstera lechleriana, a confusion the Central American revision has since undone.⁴
The confusion runs the other way too. Herbarium sheets of the montane Monstera juliusii have been filed under Monstera standleyana, though that species has fenestrate, sometimes pinnatilobed leaves and lives at 1800 to 2200 m.⁴ And Monstera gigas, whose entire leaves can exceed 3 m, passed for a giant Monstera standleyana until 2021, when it was separated by its shorter petiole sheath, gray-drying blades, and a stigma with a tubular extension.⁷
The plant itself is common in lowland moist forest on the Caribbean slope and highly variable in size, with leaves to 160 cm. In the Gandoca-Manzanillo refuge on the southern Caribbean coast individuals carry both entire and fenestrate leaves and have never been seen in flower.⁴
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera standleyana G.S.Bunting
2. Baileya 14: 133 (1967) — protologue.
3. iNaturalist: Monstera standleyana
Additional photo by Patrick Blanc
Additional photos by David Scherberich
Additional photos from iNaturalist by Eric Knight, Daniel Garrigues, Terry, Oliver Ingold, Marcel Esquivel, Finca Dinámica, Benjamin Gorfer and Fraser Watson