Planta terrestris aut epiphytica; intemodis 2.5-4.5 cm longis, apice brevioribus; cataphyllum persistens reticulo fibrarum; petiolus subteres, anguste sulcatus, 9-22 cm longus; lamina subcoriacea, ovata ad anguste-ovata, basi obtusa rotundata aut attenuata, raro acuta aut subcordata (8.5-)12-22 cm longa, (4-)6.5-12.7 cm lata, utrinque dense glanduloso-punctata, paribus tri-bus venarum collectivarum; inflorescentia plus mi-nusve erecta; pedunculus teres, 17-34 cm longus; spa-tha modice membranacea, viridis, lanceolalo-oblongae, 2.5-7 cm longa, 6-17 mm lata; spadix viridis, purpureascens, 4.5-9.5 cm longus; baccae subroseae ad rubrae, obovoideae, ca. 5 mm longae.

Terrestrial or epiphytic, more or less erect; stems to ca. 1 m long, 8-12 mm diam.; inter-nodes elongate, 2.5÷4.5 cm long, in lower portion, often relatively short near the apex; leaf scars inconspicuous; roots relatively few, ca. 2 mm diam.; cataphylls 10-16 cm long, promptly weathering to a well-developed, persistent reticulum of brownish fibers.

LEAVES usually persisting only at the upper nodes; petioles subterete, narrowly and obtusely sulcate, the sulcus sometimes broader with a medial groove, 9-22 cm long, 3-5 mm diam., three-fourths as long as or sometimes longer than the blade; geniculum 1-1.5 cm long; blades subcoriaceous, weakly arched along the midrib, ovate to narrowly ovate, acuminate at apex (the acumen apiculate), usually obtuse to rounded or subcordate at the base, (8.5-)12-22 cm long, (4-)6.5-12.7 cm wide, broadest below the middle; upper surface semiglossy, densely but inconspicuously dark glandular-punctate, the lower surface semiglossy, much paler, more densely and more conspicuously dark glandular-punctate; midrib raised on both surfaces, paler than the surface above; basal veins usually 3, free to the base, 2 of these extending in smooth curves to the apex (both acting as collective veins), the third usually joining the margin in the lower one-fourth to one-third, merely etched into the surface and scarcely or not at all more prominent than the primary lateral veins; primary lateral veins 8-10 per side, departing the midrib at 30-50° angle, mostly straight to the first collective vein, etched into surface, the lateral veins between the first and second collective veins directed at the same angle or often at a broader angle more nearly approaching 90° from the midrib; interprimary veins weaker than primary lateral veins on fresh leaves but equally as prominent as the primary lateral veins on dried plants.

INFLORESCENCE more or less erect; peduncles 17-34 cm long, 2-3.5 mm diam., terete, usually considerably longer than the longest petiole; spathe moderately thin, green, the margins sometimes tinged with purple, lanceolate-oblong, 2.5-7 cm long, 6-17 mm wide, broadest in basal one-third, abruptly acuminate at apex, acute to obtuse at base, inserted at ca. 30° angle on peduncle; stipe 1-2 mm long, ca. 3 mm diam., fleshy; spadix green, becoming violet purple in age, slightly tapered and relatively blunt at apex, 4.5-9.5 cm long, 5-7 mm diam. at base, 3-4 mm diam near apex; flowers square, 2.1-3.6 mm wide in both directions, the sides straight to weakly sigmoid; 5-6 flowers visible in the principal spiral, 3-4 visible in alternate spiral; tepals semiglossy, sometimes tinged purple on inner margins; lateral tepals 1.4-2 mm wide, the inner margins broadly rounded, turned upward against the emerging pistil, the alternate pair with inner margins at least appearing concave; pistils green, weakly emergent; stigma oblong, brush-like, 0.3-0.5 mm long; stamens emerging in a regular sequence from the base, retracting completely after anthesis; anthers creamy white, ca. 0.2 mm long, ca. 0.4 mm wide; thecae oblong-elliptic, scarcely divaricate; pollen white.

INFRUCTESCENCE semi-erect, the spadix turning violet purple, to 13 cm long; berries pinkish white to red, obovoid, ca. 5 mm long (boiled up), 4 mm wide, rounded at apex; seeds 2, ellipsoid, slightly flattened, obliquely sunken at apex around the funiculus, rounded at base, 2.5-3 cm long, 1.9-2.1 mm diam., 1-1.5 mm thick, tan, with a sticky, gelatinous, transparent appendage at apex. Figs. 121 and 122.

Anthurium melastomatis is endemic to Panama in Code and San Bias Provinces at 550 to 1,100 m in premontane and lower montane rain forest. Thus far the species has been collected at two rather widely separated localities on either side of the isthmus. The population on the South American side of the isthmus sometimes has blades subcordate at the base.

The species, a member of section Porphyrochitonium, is distinguished by its slender stem, its elongate internodes, its persistent, pale, net-like weathered cataphylls, its long-petiolate, more or less ovate, glandular-punctate leaf blades with three pairs of collective veins (two of which extend to the apex), its green spathe and spadix (the latter turning purple in age), and by its pinkish white to red berries.

Anthurium melastomatis is related to both A. collinsii and A. subrotundum, which both differ in having but a single collective vein.

The name refers to the type of leaf venation that is common in the family Melastomataceae.

Map of Mesoamerican specimens with coordinates

Panama CoclŽ: 800 m, 08.39N 80.36W, 26 March 1993, Thomas B. Croat 74858 (MO).
Panama CoclŽ: 850 m, 8.39N 80.36W, 13 Sept. 1987, Thomas B. Croat 67575 (MO).
Panama CoclŽ: 89.39N 80.36W, 23 June 1988, Thomas B. Croat 68812 (MO).
Panama CoclŽ: El Copé, 880 m, 8.40N 80.36W, 27 Apr. 1992, Pena et al. 414 (MO, PMA).
Panama CoclŽ: 770 m, 08.38N 80.35W, 12 July 1994, Thomas B. Croat & Guanghua Zhu 76763 (CM, MO, OOM).
Panama CoclŽ: 1105 m,, 13 June 1978, Croat 3471 (MO).
Panama Panamá: 800-850 m, 9.20N 79.15W, 20 Nov. 1985, Gordon McPherson 7533 (MO).
Panama Panamá: 600-800 m, 9.17N 79.17W, 20-25 Apr 1985, B. Hammel & G. deNevers 13622 (CM, MO).
Panama San Blas: 350-480 m, 9.21N 78.34W, 11 Dec. 1993, Herrera, H. et al. 1486 (CM, MO, PMA).
Panama San Blas: 350-480 m, 09.21N 78.34W, 11 Diciembre 1993, Heraclio Herrera, R. Paredes y B. Obaldia 1486 .
Panama San Blas: 400-500 m,, 25 June 1986, Greg de Nevers, H. Herrera & Ernesto Gernado 8039 (MO).