Epiphyte; stems to 16 cm long, 12 cm diam.; leaf scars 2.5 cm wide; roots numerous, green, descending, 1-1.5 cm diam.; cataphylls subcoriaceous, ca. 20 cm long, acuminate at apex, drying tan (B & K Yellow-red 9/10), persisting ± intact.

LEAVES erect-spreading; petioles 20-27 cm long, 7-10 mm wide, ± quadrangular, broadly and shallowly sulcate; geniculum 3-3.5 cm long; blades lanceolate, coriaceous, 47-69 cm long, 10-19 cm wide, acuminate at apex, rounded al base, broadest at middle, the margins broadly undulate; both surfaces matte; midrib broadly and convexly raised at base above, more acutely raised toward apex, diminishing and sunken al apex, raised and square at base below, more acute toward apex; primary lateral veins numerous, departing midrib at 60°-70° angle, ± straight, arching near margin, sunken in valleys above, raised below; interprimary veins scarcely visible; collective vein arising from one of the primary lateral veins in the apical one quarter of the blade, 5-6 mm from margin, weakly sunken above, raised below.

INFLORESCENCE spreading, shorter than leaves; peduncle 33-39 cm long, 9-12 cm diam., subterete, twice as long as petioles; spathe coriaceous, dark green (B & K. Yellow-green 5/10), turning yellow, ovate-lanceolate, 16-17 cm long, ca. 4cm wide, acuminate al apex, rounded at base, inserted at ca- 45° angle on peduncle, reflexed and held parallel to peduncle; stipe 7-13 mm long in front, ca. 3 mm long in back; spadix pale lavender to violet-purple (B & K Purple 6/5 to 5/2.5), green at apex in early stages, 15-23 cm long, 1.2-3.5 cm diam. at base, 5-10 mm diam. at apex; flowers rhombic, 3-3.5 mm long, 3.1-3.6 mm wide, the sides straight to weakly sigmoid; 7-8 flowers visible in the principal spiral, 8-10 flowers visible in the alternate spiral; tepals matte, lateral tepals 1.5-1.8 mm wide, the inner margin broadly rounded; pistils scarcely emergent, green; stigma elliptic, ca. 0.6 mm long, droplets apparent for ca. I week before stamens emerge; stamens emerging promptly from near base (but usually not the lowermost spiral) or sometimes at middle, the lateral stamens emerging in ca. three quarters the length of spadix before alternates emerge; anthers yellow-orange, held inward and partially covering stigma at level of tepals, ca. 1 mm long, 1.2 mm wide; thecae oblong-ellipsoid, scarcely divaricate; pollen yellow-orange (B & K Yellow-red 8/5).

INFRUCTESCENCE pendent; spathe twisted; spadix 24-26 cm long, 2.3-2.5 mm diam.; berries bright orange, obovoid, flattened at apex, 0.8-15 mm long, pericarp thin, ± transparent, orange; mesocarp fleshy, orange with minute raphide cells; seeds 1-2, ovoid, pale yellow, tinged brown at apex and base with somewhat flattened appendage at both ends, encased in a somewhat dry, sac-like structure. Figs. 213, 214, and 217.

Anthurium validifolium is a member of section Pachyneurium. It is known for certain only from Chiriquí Province of Panama, but a cultivated plant at Las Cruccs Botanical Garden near San Vito de Java near the Panamanian border in Costa Rica may be a native to the area according to the owner, Mr. Bob Wilson. Most collections have been made in lower montane wet forest and lower montane rain forest from 1,600 to 2,000 m. One Panamanian collection was made in premontane wet forest, which corresponds to the life zone at the Las Cruces Botanical Garden. This further substantiates that A. validifolium is also native to Costa Rica. Anthurium validifolium is characterized by its large, moderately thick, lanceolate leaf blade, lavender to purple spadix. and bright orange, obovoid berries. It is perhaps most closely related to A. seibertii and A. protensum, which share a similar inflorescence and orange berries. It differs from both of those species in having broader and thicker leaf blades. Its petiole is subquadrangular and somewhat intermediate between the terete petiole of A. protensum and the sharply quadrangular petiole of A seibertii. Although this suggests A. validifolium may be a hybrid between ,A. protensum and A. seibertii, its thicker, proportionally shorter blades are not found on either of these species.
 
 

Map of Mesoamerican specimens with coordinates

Costa Rica Puntarenas: 1140 m, 08.47N 82.58W, 24 January 1989, Michael Grayum 9278 (MO).
Costa Rica Puntarenas: Canton of Coto Brus,, 6-7 March 1984, Croat 57279 (MO).
Costa Rica Puntarenas: Las Cruces Tropical Botanical Garden, 1300 m,, 11 Jan 1978, Thomas B. Croat 44445 (MO).
Costa Rica Puntarenas: Las Cruces Tropical Botanical Garden, 1200 m, 08.49N 82.58W, 6-7 March 1984, Croat 57258 (MO).
Costa Rica Puntarenas: R.I. Ujarrás; Cordillera de Talamanca, 1600-1900 m, 09.19N 83.15W, 12 March 1993, Alvaro Fernandez 633 (CR, INB).
Panama Chiriquí: Río Colorado, 1200-1400 m, 8.50N 82.43W, 17 March 1983, C. Hamilton & H. Stockwell 3532 (MO).
Panama Chiriquí:, 30 May 1970, Thomas B. Croat 10667 (B, F, GH, K, MO, NY, PMA, RSA, US).
Panama Chiriquí: 1700-2200 m, 8.53N 82.43W, 12 Oct. 1981, Knapp 1529 (MO).
Panama Chiriquí: Cerro Pelota, 1800-2000 m, 8.53N 82.43W, 10 Oct. 1981, Knapp 1497 (K, MO).
Panama Chiriquí: 1700-2200 m, 8.53N 82.43W, 12 Oct. 1981, Knapp 1522 (MO).
Panama Chiriquí: 1700-2200 m, 8.53N 82.43W, 12 Oct. 1981, Knapp 1528 (MO).
Panama Chiriquí: 1700-2200 m, 8.53N 82.43W, 12 Oct. 1981, Knapp 1523 (MO).
Panama Chiriquí: Cerro Pelota, 2300 m, 8.54N 82.43W, 10 Oct. 1981, Knapp 1513 (F, MO).
Panama Chiriquí: 1700-2200 m, 8.53N 82.43W, 12 Oct. 1981, Knapp 1526 (MO).
Panama Chiriquí:, 30 May 1970, Thomas B. Croat 10553 (MO).
Panama Chiriquí:, 30 May 1970, Thomas B. Croat 10554 (F, MO).
Panama Chiriquí: Cerro Pando,, 21 July 1971, Thomas B. Croat 15971 (MO, NY).
Panama Chiriquí: Boquete Region, 1870 m,, 21 Nov 1975, Davidse & D'Arcy 10309 (MO, PMA).
Panama Chiriquí: Río Ladrillo, 1200-1300 m,, 6 March 1911, Pittier 3052 (US).
Panama Chiriquí: 1600 m, 8.49N 82.38W, 15 June 1987, Thomas B. Croat 66204 (MO, WU).
Panama Chiriquí: 1520 m, 8.51N 82.45W, 17 Jun 1987, Croat 66321 (MO,SEL).