Philodendron alliodorum Croat & Grayum

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 : 675

Philodendron alliodorum Croat & Grayum

Material examined. Middle slopes on W side of Cerro Pirre; 07°57′N, 077°46′W; 550–760 m; 28 Jun. 1988; T. B. Croat 68868 A ( MO). Vicinity Cerro Pirre, 17 km S of El Real, along trail from base camp, along Río Perisenico; 08°01′N, 077°44′W; 100 m; 28 Jul. 1994; T. B. Croat 77175 ( MO). South of El Real along trail at base of Cerro Pirre, forest; 08°00′N, 077°45′W; 50 m; 31 Mar. 1985; G. McPherson 7079 ( MO). Parque Nacional Darién, Cerro Pirre, Rancho Frío; 08°01′16″N, 077°44′04″W; 103 m; 13 Apr. 2016; O. O. Ortiz 2536 ( PMA). Ibid.; O. O. Ortiz 2538 ( PMA). Ibid., Rancho Plástico, camino hacia la cima del Cerro; 07°59′49″N, 077°42′45″W; 636 m; 15 Apr. 2016; O. O. Ortiz 2585 ( PMA).

Identification. This species is characterized by its nomadic vine life form, relatively short petioles (less than half the length of the blades) with involute sheaths, which extend to near the base of the blade and by its reddish-brown narrow blades (when dry), with numerous primary lateral veins (10–14 pairs). In the field, it is very difficult to differentiate from P. inaequilaterum Liebm. , which differs in having rigidly scandent habit (usually appressed to host trees), broader blades, strongly unequal at base, blackish (when dry), inflorescences usually soli- tary and orange berries.

Distribution and ecology. Colombia, Costa Rica, Ecuador, Nicaragua, and Panama. This species is common throughout the semideciduous lowland forests of Cerro Pirre and less common in the mid-elevation evergreen forests (between 600 and 800 m). Individuals of P. alliodorum usually grow in large numbers on the same tree together with those of P. inaequilaterum Liebm. and Monstera spruceana (Schott) Engl.