Heteropsis oblongifolia Kunth

Ortiz, Orlando Oriel, de Stapf, María Sánchez, Baldini, Riccardo Maria & Croat, Thomas Bernard, 2019, Synopsis of aroids (Alismatales, Araceae) from Cerro Pirre (Darién Province, Panama), Check List 15 (4), pp. 651-689 : 673-674

Heteropsis oblongifolia Kunth ( Fig. 2F)

Material examined. Parque Nacional Darién, Cerro Pirre, campamento cerca del segundo mirador; 07°59′ 49″N, 077°42′43″W; 610 m; 3 Dec. 2016; O. O. Ortiz 2718 ( MO, PMA).

Identification. Heteropsis oblongifolia is recognized by its nomadic vine life form, slender and woody stems, distichous leaves, very short petioles without geniculum, simple and subcoriaceous blades, and uniform spadices with bisexual flowers. In the study area, this species does not share morphological similarities with other species of Araceae , although if seen from a distance, it could be confused with some species of Anthurium with an escandent-epiphytic habit (for example, A. obtusum ) or individuals of the family Marcgraviaceae .

Distribution and ecology. Bolivia, Brazil, Colombia, Costa Rica, Ecuador, Nicaragua, Panama, and Venezuela. This species represents a rare species on Cerro Pirre. The only existing record was in the evergreen forest near

700 m. Based on the observations made in the field, this species can reach up to 25 m high. According to Grayum (2003), this species usually flowers in the forest canopy.

Monstera adansonii subsp. laniata (Schott) Mayo & I.M. Andrade

Material examined. Río Pirre; 07°55′N, 077°44′W; 14 Jul. 1971; T. B. Croat 15487 ( MO, PMA). On ridge of Cerro Pirre, wet forest; 07°56′N, 077°42′W; 1000–1080 m; 14 Sept. 1989; G. McPherson 14084 ( MO). Parque Nacional Darién, Serranía de Pirre, Rancho Plástico; 07°59′13″ N, 077°42′28″ W; 1127 m; 30 Jul. 2016; O. O. Ortiz 2645 ( MO, PMA). Ibid.; 07°59′13″ N, 077°42′28″ W; 1127 m; 30 Jul. 2016; O. O. Ortiz 2646 ( PMA).

Identification. This taxon is characterized by having D-shaped petioles in cross section, ovate-elliptic blades, usually perforated with entire margins, unequal at the base (one side truncated to subcorded and the other side cuneate to acute), parallel secondary lateral veins, conspicuous and numerous primary lateral veins (10–20 per side), inflorescences with long peduncles (>5.0 cm long), and peduncles that equal or exceed the spadices. On Cerro Pirre, this taxon could be confused with Monstera oreophila , which differs in having the unsheathed por- tion of the petiole U-shaped in cross section and primary lateral veins more than 25 per side.

Distribution and ecology. Lesser Antilles, Brazil, Colombia, Costa Rica, Curaçao, Ecuador, El Salvador, Guatemala, Guyana, French Guiana, Honduras, Nicaragua, Panama, Peru, Suriname, and Venezuela. On Cerro Pirre, Monstera adansonii subsp. laniata is distributed uniformly throughout the elevation gradient, but its abundance is accentuated in the montane cloud forest, which is located at elevations above 1100 m.