Monstera standleyana G.S.Bunting, 1966

Croat, Thomas B., Cedeño-Fonseca, Marco & Ortiz, Orlando O., 2024, Revision of Monstera (Araceae: Monsteroideae) of Central America, Phytotaxa 656 (1), pp. 1-197 : 161-164

45. Monstera standleyana G.S.Bunting , Baileya 14: 133. 1967 [‘1966’]. ( Figs. 77 , 78 )

Type: —“ Plant cultivated in conservatory, Cornell University, from material of unknown commercial source”, Nov 1964, G.S. Bunting 1543 (holotype GH!, isotypes K!, NY!, UC, US!) .

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. 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.

Distribution and 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.

Phenology: —Flowering from April to June, August, September and October. Fruiting in January, March, October and December.

Discussion: —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 M. 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).

Additional specimens examined: — NICARAGUA. Río San Juan: Near Caño Chontaleño , 20 km NE of El Castillo, 11°08’N 084°12’W, 200 m, 18 April 1978 – 21 April 1978, D.A. Neill & P.C. Vincelli 3618 ( MO!) ; Municipio de el Castillo, Reserva Indio-Maíz , zona de amortiguamiento, estación biológica La Lupe , 11°08’N 084°21’W, 100– 200 m, 16 Marzo 1999, R.M. Rueda et al. 10428 ( MO!) ; Reserva Indio-Maíz , Municipio de el Castillo, a lo largo del Caño Chontaleño , 11°09’N 084°11’W, 150–200 m, 17 Febrero 1997, R.M. Rueda et al. 5984 ( HULE) . COSTA RICA. Alajuela: San Ramón , Peñas Blancas, R.B. Monteverde, Río Peñas Blancas , 900 m, 16 December 1987, (Fr.), W. Haber & E. Bello 7955 ( CR!) ; San Ramón, Ángeles , Reserva Forestal de San Ramón, 1 km north east of the field station, 1000 m, 2 December 1993, (Fr.), G. Herrera 6702 ( CR!) ; Primary forest , 620 m, 16 September 1972, (Fl.), R. Lent 2918 ( MO!) ; 3 mi N of San Miguel on road between Vara Blanca and Puerto Viejo, 380 m, 26 May 1976, (Fr.), T.B. Croat 35667 ( MO!) ; Cartago: Jiménez, Pejibaye, Selva , Tausito , Estribaciones de cerro que lleva a río Tausito , 1050 m, 20 January 1996, (Fr.), A. Cascante & M. Blanco 955 ( CR!) ; Turrialba, Chirripó, Along Quebrada Platanillo near confluence of Quebrada Siripi , Platanillo de Chirripó , 1135 m, 2 March 1990, (Fr.), M.H. Grayum & D. Hodel 9728 ( CR!, MO!) ; Paraiso, Valley of Jicotea , 500–700 m, 30 June 1976, (Fr.), T.B. Croat 36535 ( MO!) ; Cartago, Dulce Nombre, Jardín Botánico Lankester , 1360 m, 14 Junio 2016, (Fr.), M. Cedeño 901 ( USJ!) ; Cartago, Dulce Nombre, Jardín Botánico Lankester , 1360 m, 20 April 2016, (Fl.), M. Cedeño & M. Blanco 875 ( USJ!) ; Guanacaste: In forest on slopes of Volcan Tenorio , 1500 m, 25 August 1980, (Fl., Fr.), B.E. Hammel 9578 ( MO!) ; Heredia: Sarapiquí, La Virgen, Pastures between Río Bijagual and Río Peje, Atlantic slope of Volcán Barva, 500 m, 6 April 1986, (Fl.), M.H. Grayum & H. Rowell 6810 ( CR!, MO!) ; Limón: Pococí, Guapiles, Guápiles , Bosque Lluvioso , 350 m, 12 October 2005, (Fr.), L. Acosta 3700 ( CR!) ; Pococí, Colorado, Forests and pastures between Rio Chirripocito and Rio Sardina (‘Sardinal’ on Chirripo Atlantico quadrangle), 12 m, 21 April 1990, (Infer.), M.H. Grayum 9806 ( CR!, MO!) ; Pococí, Guapiles, Finca Bosque Lluvioso , propiedad del INBio, alrededores de la Estación, 400 m, 11 November 1999, (Fr.), A. Rodríguez 5387 ( CR!, MO!) ; Puntarenas: Coto Brus , San Vito, E.B. Las Alturas, Las Cruces Tropical Botanical Garden, 6 km W of San Vito de Java, Cultivated and native to Costa Rica species, 1200 m, 7 March 1984, (Infer.), T. Croat 57260 ( CR!, MO!) ; San José: Vázquez de Coronado, Cascajal, Braulio Carrillo National Park , along Hwy. San Jose to Siquirres Hwy, along trail to Rio Sucio, site of the Old Carrillo Station, 600 m, 30 August 1996, (Infer.), T.B. Croat 78786 ( CR!, MO!) . PANAMA. Coclé: Slopes and summit of Cerro Gaital, N of El Valle, 08°40’N 080°07’W, 1000–1400 m, 10 July 1982, S. Knapp et al. 5975 ( MO!) ; Vicinity of El Copé , N slope of Cordillera, ca. 0.5 miles N of Continental Divide at Alto Calvario , ca. 5.6 miles N of El Copé , 08°40’41”N 080°35’47”W, 800 m, 31 March 1993, T.B. Croat 75084 ( CM, MO) ; Vicinity El Copé, 5–6 miles N of El Copé, along trail which leads into the lowlands from old Riviera saw works area, 08°40’14”N 080°35’34”W - 08°41’18”N 080°35’58”W, 600–800 m, 08 July 1994, T.B. Croat & G. Zhu 77218 ( MO!, US!) ; Panamá: Capira. Summit of Cerro Campana , 08°41’19”N 079°55’18”W, 3500 f, 21 Oct 1972, M. Madison 772 ( SEL!) ; Veraguas: Santa Fe. Slopes of Cerro Tute, near Escuela Agricola Alto Piedra , NW of Santa Fé; virgin forest along trail to summit, 08°30’20”N 081°07’14”W, 1000–1050 m, 30 Nov 1979, T.B. Croat 48941 ( MO!) ; Along western fork of road beyond Escuela Agricola Alto Piedra, NW of Santa Fé , Pacific slope. 0.6 mi beyond fork in the road; virgin forest, 08°30’47”N 081°07’30”W, 1300–1350 m, 1 Dec 1979, T.B. Croat 49057 ( MO!) .

Figures

FIGURE 77. Monstera standleyana from Cartago, Costa Rica. (A) Developing inflorescence. (B) Inflorescence with open spathe, front and back views. (C) Immature infructescence. (D) Fertile flower; in lateral view (left), and longitudinal section (right). (E) Stylar plate with stigma (left) and one stamen (right). (F) Sterile flower; in lateral view (left) and in longitudinal section (right). (G) Juvenile plant. (H) Seedling. (I) Adult plant. (J) seeds. M. Cedeño et al. 875 (USJ). Image from Cedeño-Fonseca et al. (2022).

FIGURE 78. Monstera standleyana from Manzanillo, Costa Rica.Adult plant of an atypical form with fenestrate/pinnatifid leaves growing 5 m above the ground. Photo by M. Cedeño-Fonseca. (Not collected).