Monstera florescanoana Croat, T. Krömer & Acebey, Revista Mexicana de Biodiversidad

Croat, Thomas B., Cedeño-Fonseca, Marco & Ortiz, Orlando O., 2024, Revision of Monstera (Araceae: Monsteroideae) of Central America, Phytotaxa 656 (1), pp. 1-197 : 83-84

19. Monstera florescanoana Croat, T. Krömer & Acebey, Revista Mexicana de Biodiversidad 81(2): 225–228, 1A–B, 2A–D. 2010.

Type: — MEXICO. Veracruz: Comunidad Cruz Gorda, Congregación San Salvador , 990 m, 17 June, 2008, T. Krömer, J. Viccon-Esquivel, N. Martínez-Correa and J. R. Fernández-Contreras 3334 (holotype MO-6065968 !, isotypes B, K, MEXU!, US, XAL!) .

Nomadic vine, appressed-climbing. SEEDLINGS: unknown. JUVENILE PLANTS: root climbers; stems dark green, smooth, cylindrical; internodes 1–3 cm long, 0.5–9.0 mm diam.; petiole distinct, dark green and pruinose, smooth, 10–15 cm long, sheathed up to half their length, petiole sheath deciduous; unsheathed portion slightly ribbed; blades broadly ovate, strongly cordate at base, acuminate, membranous, 7–15 × 5–8 cm, not appressed to the phorophyte; fenestrations present. ADULT PLANTS: root climbers; stems dark green, smooth, cylindrical or slightly flattened, dark brownish-black, matte, smooth (superficial view), finely and closely ridged; internodes 1.8–3.0(6.0) cm long, 0.5–1.0 cm diam., 1.8–3.0 times longer than wide; petiole dark green, smooth and pruinose, 17–24 cm long, sheathed to base of the geniculum or 1 cm below it; petiole sheath persistent; geniculum smooth, 1.5 cm long; blades ovate, glaucous below, rounded to weakly subcordate at base, subcoriaceous, acuminate, drying black, yellowish or greenish, unequal, 14.3–34.0 × 5.2–20.5 cm, one side is wider (0.7–2.0 cm) than the other, 1.2–1.5 times longer than wide; midrib obtusely sunken and concolorous adaxially, narrowly rounded and concolorous abaxially (when dry); primary lateral veins 3–6 per side, departing midrib at 45–55°; fenestrations generally on both sides, sometimes lacking perforations on one side (mainly in young or pre-adult plant’s leaves), generally with 2–4 perforations in one series per side, rarely larger perforations in two series per side (adult plant’s leaves), 0–4 perforations on the narrow side of the blade, 2–4(6) perforations on the wider side, 1.5–9.5 × 0.7–4.8 cm, ellipsoid to ovate. INFLORESCENCES with a smooth, green peduncle, 2.0– 5.7 cm long; spathe long acuminate, yellow green externally at anthesis, 10–20 × 5–10 cm, up to 6 cm longer than the spadix; spadix 6.7–9.5 cm long, 2.3–3.0 cm diam., sessile or stipitate, stipe 10 mm long, drying 3 mm diam.; basal sterile flowers 3–5 mm long; fertile flowers 5–6 mm long; stamens 1–6 mm long, with laminar filaments; anthers 1.5–2.0 mm long; ovary quadrangular in longitudinal section, ribbed, 3–4 × 3.5–4.0 mm; stigma circular, deeply sunken medially when dry, black with a medial brown margin; berries with a greenish stylar cap during development, mature stylar cap color unknown; pulp unknown; seeds unknown.

Distribution and ecology: — Monstera florescanoana is endemic to Mexico, known only from the type locality in Veracruz State in the understory of the humid montane forests of the Atzalán municipio (bosque mesófilo de montaña, sensu Rzedowski, 1978 ), at 990–1430 m. This is probably the equivalent to Premontane wet forest in the Holdridge life zone system.

Phenology: —Flowering registered in May and June. Fruiting in June and October.

Discussion: —The species, a member of section Monstera , is closely related to Monstera siltepecana Matuda , from which it differs in having smaller petioles and geniculum, and blades that are glaucous below on living plants, fewer perforations that are only in 1 (rarely 2) series on each side and fewer primary lateral veins, a frequently persistent petiole sheath and a smaller inflorescence (peduncle and spadix). On the other hand, it shares with M. siltepecana the same drying color and texture, even the same venation.

Monstera florescanoana may also be confused with Monstera dubia , but Monstera dubia differs in having typically thicker stems which are usually densely tuberculate, leaf blades thicker with more conspicuous tertiary venation, larger petioles, geniculum and leaves, as well as a larger inflorescence.

Additional specimens examined: — MEXICO. Hidalgo: Tlanchinol. m, I. Luna et al. 618 (MEXU!); Querétaro: 1.5 km al sureste de Neblinas, municipio de Landa. Bosque de Lonchocarpus y Ulmus , ladera de cerro, 800 m, 27 Jun 1990, H. Rubio 1764 (MO!); 1.5 km al noroeste de El Humo, municipio de Landa. Bosque de encino- somerio, ladera de cerro, 1070 m, 9 May 1989, H. Rubio 652 (MO!); Landa de Matamoros. Los Tubos, 3 km al Norte de San Juan. Bosque de Liquidambar, orilla de arroyo, cañada, 1000 m, 19 Sep 1988, H. Rubio 151 (MO!); 4 km al N de Agua Zarca. Bosque mesófilo de montaña, 21°13’48”N 099°05’24”W, 700 m, 31 Jul 1991, S. Zamudio & E. Carranza 8236 (MO!); Veracruz: Communidad Cruz Gorda, Congregación San Salvador. Bosque mosófilo de Montaña, 19°52’30”N 097°12’43”W, 990 m, 17 June 2008, T. Krömer et al. 3334 (B, K, MEXU, MO, US, XAL).