MONSTERA TACANAENSIS
PROTOLOGUE: Monstera tacanaensis Matuda, published in Anales del Instituto de Biología, Universidad Nacional Autónoma de México, Serie Botánica 43, Ser. Bot. (1): 55 (1972). The protologue is reproduced below.
DISTRIBUTION: Mexico (Chiapas) to Guatemala, Costa Rica to Panama: Chiapas, Costa Rica, Guatemala, Mexico Southeast, Panama.
DISTRIBUTION NOTE: Costa Rica: Cartago, Guanacaste, Heredia, Limón Mexico: Chiapas Panama: Bocas del Toro, Coclé, Veraguas iNaturalist: Alajuela, Chiriquí, Puntarenas, San José.
SPECIES DESCRIPTION:
Terrestrial plant in walls or nomadic vine from the canopy, appressed-climbing and pendent habit. Seedlings: bearing foliose leaves. Juvenile plants: root climbers; stems light-green, smooth, cylindrical; internodes 10–18 cm long, 1.0–1.5 cm diam.; petiole distinct, 9–20 cm long; blades ovate, subcordate to truncate at base, acuminate at apex, coriaceous, 10–17 × 8–13 cm, not appressed to the phorophyte; fenestrations absent or present. Adult plants: root climbers; stems light-green to dark-green, cylindrical; internodes 8–15 cm long, 1.5–2.0 cm diam., 5.3–7.5 times longer than wide; cataphylls light green or yellowish, deciduous but leaving dry fragments on the peduncle; anchor roots slender, black; feeder roots grayish, corky; petiole dark-green with black dots, smooth, 20–50 cm long, sheathed up to medial part or 6 cm before base of the geniculum; petiole sheath deciduous; unsheathed portion slightly terete; geniculum smooth, flattened adaxially, cylindrical convex abaxially, 2–5 cm long; blades ovate to sub-orbicular, cordate at base, acuminate at apex, subcoriaceous to coriaceous, drying brownish, yellowish or grayish, 18–55 × 18–45 cm, not decurrent on geniculum; midrib flattened and prominent adaxially, convex abaxially, drying yellowish or brownish on both surfaces; primary lateral veins 4–7 per side, prominent on both surfaces, departing midrib at 85–90°, drying yellowish, brownish or blackish; secondary veins slightly prominent; collective veins not visible; fenestrations absent or present, perforations arranged on each side next to the midrib; margins entire or pinnatilobed, 2–5 lobes per side, the perforations between the lobes break, causing a hook-like structure.⁴
INFLORESCENCE:
Inflorescences on ascending or pendent stems, 1–5 simultaneously at flowering time, arranged in the axils of the leaves or into cataphylls; peduncle smooth and pruinose from the middle towards the apex, 8–13 cm long; spathe obtuse to short-acuminate, light-green or grayish and completely pruinose during development, pale-pink internally and light-green externally and less pruinose at anthesis, the margins revolute, completely open at apex, deciduous or marcescent after anthesis 13–16 × 10–13 cm, up to 2 cm longer than spadix; spadix cream-colored during development and anthesis, 5–15 cm long, 2.0–3.5 cm diam.; basal sterile flowers 4–6 mm long, with a transparent stigmatic secretion; fertile flowers 5–9 mm long; stamens 0.5–9.0 mm long, with laminar filaments; anthers 2–3 mm long; ovary quadrangular in longitudinal section, ribbed, 4–5 × 4–5 mm; style hexagonal, 1.5–2.0 × 5–7 mm; stigma linear, sunken on style; berries with a dark-green stylar cap during development, mature stylar cap moss-green; pulp creamy-white; seeds dark green, obovoid, 10–15 mm long, extruded from the fruit when ripe.⁴
ECOLOGY:
In Costa Rica it is distributed in both watersheds of the Cordilleras de Guanacaste, Tilarán, Central and Talamanca, (Often occurring along the Continental divide and south of the fila Costeña, at 550–2400 m. It lives in Tropical wet forest, Premontane wet forest, Premontane rain forest and Lower montane rain forest life zones. Inflorescences and infructescences have been collected throughout the year; proper anthesis has been recorded in October-November.⁴
ETYMOLOGY:
The epithet refers to Volcán Tacaná, the volcano on the border of Chiapas, Mexico, and Guatemala from which the species was described.²
NOTES:
1. The species, a member of sect. Tornelia, is distinguished from other species by its smooth, deep green, pruinose petioles (sometimes with black dots), cylindrical or almost so between the sheath apex and the geniculum, the geniculum lacking wings, shallowly cordate leaf blades with few perforations or none (when present, all of similar size, and only one between successive primary lateral veins), the spathe green and pruinose externally and pinkish cream internally, and a relatively short spadix (5–15 cm long) that turns dark bluish-green to dark brown during fruit development. Monstera tacanaensis had been considered a synonym of Monstera deliciosa (Cedeño-Fonseca et al. 2020c, 2022). However, the latter has usually thicker stems with a lower internode length-to-width ratio, petioles commonly (but not always) verrucose and distally winged, sheath wings with a small apical ligule, leaf blades deeply cordate, that can have up to 15 fenestrations of very different sizes between successive primary lateral veins, the spathe yellowish externally and cream internally, a relatively long spadix (10–23 cm) with many more florets, and low, cupuliform stigmatophores. The developing fruits of Monstera deliciosa turn deep green externally, but never as dark as in Monstera tacanaensis. No pruinosity can be seen on the petioles and spathe of Monstera deliciosa. For more details about the taxonomic comments and nomenclatural notes see Cedeño-Fonseca et al. (2022).⁴
2. Conservation status: Monstera tacanaensis is protected in the Reserva Biológica Las Cruces, Jardín Botánico Wilson, Jardín Botánico Lankester, Parque Nacional Volcán Tenorio, Parque Nacional Braulio Carrillo, Parque Nacional Volcán Arenal, Parque Nacional Tapantí and Parque Internacional de La Amistad.⁵
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Monstera tacanaensis Matuda
2. Anales del Instituto de Biología, Universidad Nacional Autónoma de México, Serie Botánica 43, Ser. Bot. (1): 55 (1972) — protologue.
3. iNaturalist: Monstera tacanaensis
Additional photos from iNaturalist by steve_the_green, Chuck Sexton, Oliver Ingold, Peter Marting, Marcel Esquivel, Original madness, oliversanmartin, Andreas Berger, blistr, Art Riz, Daniel Garrigues, Alexa Skordi, bdrury, Chris Kettinger, David Garrigues, Eric Knight, ericggow, Francis Mariani, jeanh, jfunk, Lee, Mauricio Cordero, ramon_d, Rebecca Hill, Rucks, ur6s77, Víctor González García and Ángel Argüelles