Monstera anomala Zuluaga & Croat, Phytotaxa

Croat, Thomas B., Cedeño-Fonseca, Marco & Ortiz, Orlando O., 2024, Revision of Monstera (Araceae: Monsteroideae) of Central America, Phytotaxa 656 (1), pp. 1-197 : 38-41

6. Monstera anomala Zuluaga & Croat, Phytotaxa 334: 2–6, f. 1A–F, 2A–D. 2018. ( Figs. 12 , 13 )

Type: — PANAMA. Veraguas: Distrito Santa Fe, corregimiento El Pantano, Parque Nacional Santa Fe , trail between alto Los Gonzales to alto El Viro , 800–1000 m. 16 Jan 2013, A. Zuluaga, A. Doucette, E. Brantner & E. González 888 (holotype WIS, isotypes PMA!, MO!) .

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. 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.

Distribution and ecology: — Monstera anomala occurs in Costa Rica and western Panama, at 100–1200 m in Premontane rain forest and Montane rain forest life zones.

Phenology: —Flowering has been recorded in February, March but primarily August-November. Fruiting in May, July and again in September-December.

Discussion: —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 M. 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. M. 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 M. 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.

Additional specimens examined: — COSTA RICA. Cartago: Turrialba, Chirripó , Along Quebrada Platanillo near confluence of Quebrada Siripi , Platanillo de Chirripó , 1135 m, 2 March 1990, (Infer.), M.H. Grayum & R. Hodel 9727 ( CR!) ; Heredia: Sarapiquí, La Virgen, E.B. La Selva, Finca La Selva, Puerto Viejo de Sarapiquí , Ridge near and of Pasos Perdidos, 120 m, 3 June 1985, (Infer.), M.H. Grayum et al. 5356 ( CR!) ; Limón: Talamanca, Bribri, R.V.S.M. Manzanillo, 20 m, 3 March 2018, (Fl.), M. Cedeño 1333 ( USJ!) ; Talamanca, Telire, Alto Urén , subiendo a Cerro Chum, siguiendo un antiguo camino de Quebrada Chaho a Alto Lari, 800 m, 24 July 1989, (Fr.), G. Herrera 3330 ( CR!) ; Talamanca, Cahuita, Along road between Puerto Viejo de Talamanca and Manzanillo , stretch from Quebrada Ernesto to Manzanillo, 5 m, 3 November 1984, (Fr.), M.H. Grayum & P. Sleeper 4352 ( CR!, MO!) ; Pococí, Colorado, Hills 3 1/2 airline km S of Islas Buena Vista in the Rìo Colorado, 16 airline km SW of Barra del Colorado, Premontane wet forest on low hills, 110 m, 15 September 1986, (Fl.), G. Davidse & G. Herrera 31269 ( CR!) ; Limón, Río Blanco, Las Brisas de Veragua , Propiedad de Veragua Rainforest, Sendero que va del serpentario hacia el Río Victoría, 356 m, 26 May 2011, (Fr.), A. Cascante et al. 2299 ( CR!) ; Pococí, Colorado, R.N. V.S. Barra del Colorado , Forests and pastures between Río Chirripocito and pastures between Río Chirripocito and Río Sardina (”Sardinal” on Chirripó Atlántico quadrangle), 12 m, 21 April 1990, (Infer.), M.H. Grayum 9809 ( CR!) ; Pococí, Rita, Cuenca Tortuguero-Sierpe , 40 m, 5 February 1988, (Infer.), M.H. Grayum 11165 ( CR!) ; Limón, Valle de la Estrella , Cuenca del Estrella, Hitoy Cerere, Sendero a los alrededores de la Estación, 90 m, 19 June 1997, (Fr.), A. Rodríguez & A. Soto 2320 ( CR!) ; Puntarenas: Golfito , Golfito, R.N. V.S. Golfito, Cabecerass de la quebrada Cañaza, 150 m, 3 March 1994, (Fr.), G. Herrera & G. Rivera 7004 ( CR!) ; Osa, Sierpe, Boca Ganado , Estribaciones de Fila Ganado , 350 m, 24 November 1993, (Fr.), G. Herrera et al. 6684 ( CR!) ; Osa, Sierpe, Along road between Rincón de Osa and Rancho Quemado and Rancho Quemado, ca. 10 km W of Rincón-Pto. Jimenez Road, 175 m, 3 March 1985, (Infer.), T.B. Croat & M.H. Grayum 59783 ( CR!) ; Osa, Sierpe, Along road between Rincón de Osa and Rancho Quemado, ca. 10 km W of Rincón-Pto. Jiménez Road, 180 m, 3 March 1985, (Infer.), T.B. Croat 59755 ( CR!, MO!); Golfito, Golfito, Cuenca del Coto Colorado, 60 m, 10 September 1996, (Infer.), T.B. Croat 67585 ( CR!) ; Osa, Sierpe, Cuenca Térraba-Sierpe , 10 m, 13 November 2002, (Infer.), T.B. Croat 79200 ( CR!) ; Osa , Bahía Ballena , Ballena , 200 m, 22 January 1997, (Fr.), J. Gonzáles 2324 ( CR!) ; Rincón de Osa ; along ridge between Quebrada Aparicio and Quebrada Aguabuena, 200–400 m, 7 October 1984, (Fl.), M.H. Grayum 4015 ( MO!) ; San José: Pérez Zeledón, Río Nuevo , Savegre Abajo de Río Nuevo, Cerro El Zoncho , 900 m, 11 February 1999, (Fl.), A. Estrada et al. 2043 ( CR!) .

Figures

FIGURE 12. Monstera anomala from Costa Rica. (A) Developing inflorescence. (B) Open inflorescence, frontal view, with tearing spathe. (C) Immature infructescence. (D) Portion of juvenile plant. (E) Portion of adult plant. (F) Fertile flower; in lateral view (left) and longitudinal section (right). (G) Stylar plate with stigma (left) and one stamen (right). (H) Sterile flower; in lateral view (left) and longitudinal section (right). Golfito, Costa Rica. (Not collected). Image from Cedeño-Fonseca et al. (2022).

FIGURE 13. Monstera anomala. Adult plant growing 20 m above the ground in a tree in Turrialba, Costa Rica. Photo by M. Cedeño- Fonseca. (Not collected).