Monstera bocatorensis Croat & M. Cedeño, Webbia

Croat, Thomas B., Cedeño-Fonseca, Marco & Ortiz, Orlando O., 2024, Revision of Monstera (Araceae: Monsteroideae) of Central America, Phytotaxa 656 (1), pp. 1-197 : 41-44

7. Monstera bocatorensis Croat & M. Cedeño, Webbia 76(2): 266–269. 2021. ( Figs. 14 , 15 )

Type: — Panama. Bocas del Toro. Along road between Chiriquí Grande and Fortuna , 7.7 mi W of Chiriquí Grande , 1.5 mi W of Punta Peña, disturbed primary forest, 80 m, 9 Mar. 1985, T.B. Croat & M.H. Grayum 60088 (holotype MO-3123561 !, isotypes B!, COL!, K!, PMA!, NY!, US!).

Robust nomadic vine, appressed-climbing. SEEDLINGS: bearing foliose leaves. JUVENILE PLANTS: root climbers; stems completely terrestrial or ascending, dark green, smooth and glaucous, cylindrical; internodes 0.5–4.0 cm long, 0.5–1.0 cm diam.; petiole dark or light green, smooth and glaucous at base, 8–20 cm long, sheathed for 3–7 cm, or up to the middle; petiole sheath persistent and involute; unsheathed portion terete; leaf blades ovate to ellipticovate, attenuate at base, acuminate at apex, thinly coriaceous, 10–25 × 6–10 cm, not appressed to the phorophyte; fenestrations absent or present (usually one fenestrated side which breaks at the margin). ADULT PLANTS: root climbers; stems dark green or shiny beige, cylindrical and slightly flattened; internodes 1.0– 2.5 cm long, 1.5–3.0 cm diam., 0.4–0.8 times as long as wide; cataphylls with a very small blade at the apex, persistent, light green to pruinose; anchor roots light brown, with root trichomes; feeder roots light brown, with root trichomes; petiole light green or dark green, smooth and glaucous throughout, 46–90 cm long, sheathed up to the middle or 5–15 cm beyond the middle; petiole sheath persistent and involute; unsheathed portion terete and slightly ribbed near the geniculum; geniculum sunken adaxially and convex abaxially, 2.0– 3.5 cm long; leaf-blades ovate to oblong-ovate, rounded at base, short-acuminate at apex, subcoriaceous, (31)48–58 × (13) 20–32 cm, 1.7–2.0(2.6) times longer than wide, not decurrent on the geniculum; midrib ribbed adaxially, convex abaxially; primary lateral veins 14–20 per side, departing midrib at 60–90°, strongly sunken adaxially, prominent abaxially; secondary veins completely parallel; collective veins scarcely visible on the margins of each lobe; perforations absent; margins deeply pinnatifid or rarely entire, generally with 2–6 lobes per side, 3–20 cm wide, with 3–10 veins per lobe. INFLORESCENCES on ascending stems, 1 or 2 simultaneously in flowering season; peduncle smooth, light green or dark green, 27–45 cm long, 1 cm diam., entirely covered by cataphylls; spathe acuminate, membranous, completely open, with margins overlapping at base, light green during development, creamy or white externally and white with longitudinal greenish or white veins internally at anthesis, 12–17 × 5–9 cm, up to 6 cm longer than the spadix; spadix white during development and at anthesis, 11–12 cm long, 1.7–2.2 cm diam.; basal sterile flowers 3–5 mm long, globose and with a very prominent stigmatophore and an orange stigmatic secretion; fertile flowers 5–6 mm long; stamens 1.5–5.0 mm long, with laminar filaments; anthers 1–2 mm long; ovary quadrangular in longitudinal section, 1.5–2.5 × 1.5–2.0 mm; style quadrangular, cylindrical, or hexagonal, 0.5–1.0 × 2–3 mm; stigmatophore columnar, slightly ribbed on style, 0.5–1.0 mm long; stigma linear with a transparent stigmatic secretion; berries with green stylar cap during development, unknown when ripe; pulp unknown; seeds unknown.

Distribution and ecology: — Monstera bocatorensis is endemic to Panama, where it is known only from the western slopes of the mountains east of Fortuna Dam below the Continental Divide in Bocas del Toro Province, from sea level to 1100 m in Tropical wet forest and Premontane wet forest life zones.

Phenology: —Flowering in September. Fruiting in March, June, September and October.

Discussion: —The species is a member of sect. Monstera and is characterized by its ovate, yellowish-drying leaf-blades that are never perforate, frequently pinnatifid with two or three very unequal pinnae, or rarely entire. Other characteristic features are the short petiole sheaths that extend only to the middle or ¾ of its length, as well as the glaucous petioles and blades.

This species is similar to M. glaucescens but differs from that species by its leaf-blades drying light yellow-brown on the lower surface and by having the pinnae markedly unequal. In contrast, the leaves of M. glaucescens have blades that dry dark brown and have much narrower pinnae, with more long-tapered and more prominently falcate pointed lobes. Another species with which it could be confused is Monstera croatii but that species differs by its deeply pinnatifid and bluish green leaf blades, with bifid lobes, a persistent sheathing mucronate cataphyll, and spathe with two longitudinal keels.

Additional specimens examined: — PANAMA. Bocas del Toro: La Fortuna area to increase Chiriquí Grande and the oil pipeline; along dirt road 10 mi from continental divide, just past 2nd large bridge; 1 mi north from highway, 08°46’N 082°11’W, 130 m, 05 March 1986, B.E. Hammel et al. 14599 ( MO!) ; Vicinity of Chiriquí Grande, near town of Rembala [Rambala], on trail west of road. [Coordinates on orginal label: 08º45’N 82º15’W], 08°56’16”N 082°12’19”W, 250 m, 30 June 1987, G. McPherson 11150 ( MO!) ; Laguna de Chiriqui, rincon SE. Nuri: campamento cerca poblacion Guaymi. 15 km W de Puntas Cricamola, entrando Ensenada de Catavela , y subiendo Quebrada Nuri , 08°55’N 081°49’W, 10–25 m, 19 Mar 1993, R.B. Foster et al. 14604 ( PMA!) ; Along road between Chiriquí Grande and Fortuna , 7.7 miles W of Chiriquí Grande , 1.5 miles W of Punta Peña, 08°53’36”N 082°11’12”W, 80 m, 09 March 1985, T.B. Croat & M.H. Grayum 60088 ( MO!) .

Figures

FIGURE 14. Monstera bocatorensis from Santa Fe, Panama. (A) Front view of open inflorescence. (B) Developing inflorescence. (C) Front view of open inflorescence with peduncle and persistent cataphyll. (D) Back view of open inflorescence. (E) Juvenile plant. (F) Adult plant. (G) View of spadix at female anthesis, showing flowers with stigmatophore lateral-flattened. Image from Cedeño-Fonseca et al. (2020b).

FIGURE 15. Monstera bocatorensis from Santa Fe, Panama. (A) Adult plant, leaf-blades with 4–6 lobes per side. (B) Adult plant, one leaf-blade entire and one with 2 or 3 lobes per side. (C) Adult plant, leaf-blade with 2 or 3 lobes per side. (D) Spathe, marcescent after male anthesis and enclosing the spadix. Image from Cedeño-Fonseca et al. (2020b).