MONSTERA ANOMALA
PROTOLOGUE: Monstera anomala Zuluaga & Croat, published in Phytotaxa 334: 2 (2018).
DISTRIBUTION: Costa Rica to W. Panama: Costa Rica, Panama.
DISTRIBUTION NOTE: Panama: Veraguas iNaturalist: Limón, Puntarenas.
SPECIES DESCRIPTION:
Robust nomadic vine, appressed-climbing. Seedlings: filiform. Juvenile plants: root climbers; stems light-green, smooth to slightly rough, flattened; internodes 3–5 cm long, 3–8 mm diam.; petiole distinct, dark-green, smooth, 5–7 mm long, sheathed to base of the geniculum; petiole sheath deciduous; blades ovate, cordate at base, obtuse to short acuminate, coriaceous, 6–9 × 6–8 cm, completely appressed to the phorophyte; fenestrations absent. Adult plants: root climbers; stems light green to grayish, slightly rough, cylindrical or slightly flattened, sulcate laterally; internodes 1.0–3.5 cm long, 1–3 cm diam., as long as wide; anchor roots black; feeder roots light brown, corky; petiole light-green, smooth, sometimes verrucose at base, 15–50 cm long, sheathed up to the middle of the geniculum; petiole sheath deciduous, with fibrous remains; geniculum smooth or pustular, slightly flattened or ribbed adaxially, 2.0–4.5 cm long; blades narrowly lanceolate or lanceolate, oblique, broadly-cuneate to attenuate at base, acuminate at apex, subcoriaceous to thinly coriaceous, drying gray, brown, yellowish-green or olive-green, 25–55 × 10–25 cm, 2.1–4.2 times longer than wide, slightly decurrent on the geniculum (decurrent part 2–3 mm wide); midrib sunken adaxially, convex abaxially, drying yellowish or blackish on both surfaces; primary lateral veins 4–25 per side, obscure adaxially, prominent abaxially, departing midrib at 35–50°, drying yellowish or blackish; secondary veins prominent and reticulate towards the margin; collective veins slightly visible; fenestrations absent; margins entire.⁴
INFLORESCENCE:
Inflorescences on ascending stems, 1–2 simultaneously at the flowering season, arranged in the leaf axils; peduncle smooth or slightly verrucose, 3–11 cm long, 0.6–1.4 cm diam.; spathe obtuse or mucronate, light-green during development, light-green externally and white internally at anthesis, coriaceous, deciduous after anthesis, 10–20 × 7–10 cm, as long as the spadix; spadix green-yellow during development, creamy-yellowish at anthesis, 10– 24 cm long, 2–4 cm diam., 1.7–2.8 times longer than the peduncle; basal sterile flowers with a transparent stigmatic secretion, 4–6 mm long; fertile flowers 1.0–2.2 cm long; stamens 3–6 mm long, with laminar filaments; anthers 1.5– 2.0 mm long; ovary quadrangular in longitudinal section, 6–10 × 2.5–5.0 mm; style thin and elongated at the medial part, distal region pentagonal, 4–6 × 1.5–2.5 mm; stigma linear, with a yellowish stigmatic secretion; berries with a yellow stylar cap, greenish during development; pulp white; seeds black, spherical, 4–6 mm long.⁴
ECOLOGY:
Monstera anomala occurs in Costa Rica and western Panama, at 100–1200 m in Premontane rain forest and Montane rain forest life zones. Flowering has been recorded in February, March but primarily August-November. Fruiting in May, July and again in September-December.⁴
ETYMOLOGY:
From Greek anōmalos, "irregular" or "anomalous," presumably referring to a feature the authors found unusual for the genus; the explanation given in the protologue is not repeated in later treatments.
NOTES:
1. The species is a member of sect. Marcgraviopsis and is characterized by its high-climbing hemiepiphytic habit, internodes slightly longer than wide, petioles sheathed to the geniculum with a marcescent sheath and turning light brown, mostly entire, non-perforated elliptic to oblong, mostly weakly acuminate blades which are slightly bicolorous with 10–15 primary lateral veins per side as well as by the solitary, erect inflorescence with the peduncle much shorter than the white spadix but especially by the constricted stylar region. Monstera anomala is easy to distinguish from other species in the genus with shingled leaves and with its flowers with a long and constricted stylar region, 4–6 mm long, which is narrower than the ovary. It is most similar to Monstera acuminata but adult plants are more robust, with coriaceous entire leaves, that lack perforations, and with primary and secondary veins inconspicuous on the upper surface. Monstera acuminata, a widespread species from Mexico to Nicaragua, differs by having proportionately wider leaves with more prominent secondary lateral veins on the lower surface and a broad style that is as wide as the ovary. Monstera anomala is also similar to Monstera spruceana and was confused with that species (Grayum, 2003). Monstera spruceana differs by being a typically more robust plant with deeply pinnate lobed leaves, as well as often drying more blackened and by having the typical Monstera stigma which is only weakly raised and oblong, extending most of the way across the apex of the style.⁴
2. Conservation status: Monstera anomala is protected in the Estación Biológica La Selva, Reserva Biológica La Tirimbina, Reserva Biológica Alberto Manuel Brenes, Parque Nacional Corcovado, El Refugio Nacional de Vida Silvestre Barra del Colorado and Refugio Nacional de Vida Silvestre Golfito.⁵
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera anomala Zuluaga & Croat
2. Phytotaxa 334: 2 (2018) — protologue.
3. iNaturalist: Monstera anomala
Additional photos from iNaturalist by Eidiu, Hans Holbrook, Noah M. Morales, Marcel Esquivel, Leonardo Álvarez-Alcázar, Owen Ridgen, alexguthrie and Oliver Ingold