Philodendron pirrense Croat

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 : 680-681

Philodendron pirrense Croat ( Fig. 8C)

Material examined. Middle slopes on W side of Cerro Pirre; 07°56′N, 077°45′W; 800–1050 m; 29 Jun. 1988; T. B. Croat 68952 ( 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 2636 ( MO, PMA).

Identification. This species is distinguished by having

short internodes, persistent and fibrous reddish cata- phylls, slightly flattened petioles adaxially, reddish when dry, broadly ovate and cordate with well-developed posterior ribs, seven to 11 pairs of basal veins, inflorescences up to four per node, whitish peduncles, and spathe tubes reddish externally. On Cerro Pirre, this species can be confused with Philodendron fragrantissimum (Hook.) G. Don , but the latter species generally ocurrs in areas below 800 m and differs in having smaller blades with fewer pairs of basal veins (usually four per side).

Distribution and ecology. Endemic to Panama. Philo-

dendron pirrense represents an extremely rare species. On Cerro Pirre, ocurrs in premontane and montane forests, above 1000 m.