Revision of Monstera (Araceae: Monsteroideae) of Central America Author Croat, Thomas B. 0000-0002-1804-0532 P. A. Schulze Curator, Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110, U. S. A. & email: thomas. croat @ mobot. org; https: // orcid. org / 0000 - 0002 - 1804 - 0532 thomas.croat@mobot.org Author Cedeño-Fonseca, Marco 0000-0003-0119-0427 P. A. Schulze Curator, Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110, U. S. A. & Botanischer Garten und Botanisches Museum Berlin, Freie Universität Berlin, Königin-Luise-Strasse 6 - 8, D- 14195 Berlin, Germany. & Herbario Luis Fournier Origgi (USJ), Centro de Investigación en Biodiversidad y Ecología Tropical, Universidad de Costa Rica, Apdo. 11501 - 2060, San José, Costa Rica. & Jardín Botánico Lankester, Universidad de Costa Rica, Apartado 302 - 7050 Cartago, Costa Rica. & email: marcovf. 09 @ gmail. com; https: // orcid. org / 0000 - 0003 - 0119 - 0427 marcovf.09@gmail.com Author Ortiz, Orlando O. 0000-0002-7805-0046 P. A. Schulze Curator, Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110, U. S. A. & Botanischer Garten und Botanisches Museum Berlin, Freie Universität Berlin, Königin-Luise-Strasse 6 - 8, D- 14195 Berlin, Germany. & P. A. Schulze Curator, Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110, U. S. A. & Herbario PMA, Universidad de Panamá, Estafeta Universitaria, Panama City, Republic of Panamá. & P. A. Schulze Curator, Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110, U. S. A. & Coiba Scientific Station (COIBA AIP), Clayton, Panama City, Panama. & P. A. Schulze Curator, Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110, U. S. A. & email: ortizopma @ gmail. com; https: // orcid. org / 0000 - 0002 - 7805 - 0046 * Corresponding author. e-mail: marcovf. 09 @ gmail. com & P. A. Schulze Curator, Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110, U. S. A. ortizopma@gmail.com text Phytotaxa 2024 2024-06-27 656 1 1 197 http://dx.doi.org/10.11646/phytotaxa.656.1.1 journal article 10.11646/phytotaxa.656.1.1 1179-3163 13213072 20. Monstera gambensis M. Cedeño & M.A. Blanco, Webbia 75(1): 123–132. 2020 . ( Figs. 36 , 37 ) Type: — COSTA RICA . Puntarenas Province , Golfito Cantón , Golfito , La Gamba , sendero sobre quebrada, 94 m , 27 May 2016 , M. Cedeño , A.P. Karremans & I. Chinchilla 890 ( holotype USJ !) . Nomadic vine, appressed-climbing. SEEDLINGS: unknown. JUVENILE PLANTS: root climbers; appressed-climbing; stem dark green, slightly rough; internodes 3–5 cm long, 4–10 mm diam.; petioles visible (i.e., the leaves not shingling), dark green or light, slightly rough, 3–5 cm long, sheathed to base of the geniculum; petiole sheath persistent; blades more or less horizontal, not flattened to the substrate of the phorophyte, 4–7 × 3–4 cm , obovate or lanceolate, subcordate to truncate at base, acuminate at the apex, thinly coriaceous, without fenestrations. ADULT PLANTS: root climbers; stem terete, dark green, rough; internodes 1–4 cm long, 0.5–1.0 cm diam., 2–3 times longer than wide; anchor roots black and corky, 4–6 cm long, feeder roots black and semi-corky, both with black root hairs; petioles light green or whitish, rough to the geniculum, 17–22 cm long, sheathed to 2–3 cm below base of the geniculum; petiole sheath involute and persistent, the free portion slightly grooved; geniculum elongate, 0.5–1.0 cm long; blades lanceolate, attenuate at base, acuminate at the apex, subcoriaceous, 12–24 × 5–10 cm , decurrent on the geniculum (the decurrent part 0.5–1 mm wide); midrib convex to the middle of the blade abaxially, slightly rough; primary lateral veins 5–13 per side, impressed or indistinct abaxially, prominent on the underside, departing midrib at 35–45°; fenestrations (when present) one or two close to each other on the same side of the blade near its middle part; collective veins not visible; margins entire. INFLORESCENCES on ascending stems; peduncle rough throughout, 20–25 cm long; spathe unknown; spadix 7–10 × 1.3–1.6 cm , color unknown; basal sterile flowers 3–4 mm long; fertile flowers 4–5 mm long; stamens 2–4 mm long, with laminar filaments; anther 1–2 mm long; ovary prismatic, longitudinally ribbed, 2–3 × 2–3 mm ; style hexagonal, 1–2 × 3–5 mm ; stigma linear; berries yellow when ripe; pulp white; seeds black, 2–3 mm long. Distribution and ecology: —Endemic to Costa Rica , where it has been found growing low on the supporting trees (ca. 2 m above ground level), in rain forest at La Gamba Biological Station, Cantón Golfito, mostly at 50–100 m , in Tropical wet forest life zones. FIGURE 36. Monstera gambensis from Golfito, Costa Rica. (A) Adult plant with non-perforated leaves. (B) Juvenile plant. M. Cedeño et al. 890 (USJ). Image from Cedeño-Fonseca et al. (2020d) . Phenology: —Flowering has not been observed, fruiting was recorded in May. Discussion: —The species, a member of section Monstera , differs from other species by its rough whitish stem and petioles, its persistent entire involute petiole sheath, and entire adult leaf blade with or without fenestrations. In size it is similar to Monstera obliqua , but it is differentiated by having smaller leaves (12 × 5 vs. 35 × 14 cm ), rough petiole (vs. smooth), and persistent petiole sheath (vs. deciduous). In Costa Rica , Monstera obliqua is found only in the extreme southeast of the country (Caribbean slope, Grayum 2003 ), while M. gambensis is known only from a single collection in La Gamba de Golfito (Pacific slope). This species is also similar to Monstera minima but that has smaller petioles ( 2–6 cm ), leaf blades (9–14 × 2–4 cm ), and spadices (ca. 4.4 × 09– 1 cm ) and is only known from the northern (Caribbean) coast of Panama and along the Pacific slope of northern Colombia , in the Chocó region ( Jácome & Croat 2002 ). In Costa Rica , Monstera gambensis is found in lowland tropical wet forest at elevations up to ca. 100 m . The individuals observed were climbing in undisturbed forest on small trees no more than 2.5 m high, with abundant shade in the understory.