Anthurium gracillimum Engler, Bot. Jahrb. Syst. XXV. 371. (1898). Syn. nov. Type: Colombia. Valle: Buenaventura, Lehmann 3826 (holotype, B).

Epiphytic; stem short to scandent; internodes 1–8 cm long, 5–20 mm wide, semi glossy, medium green to gray, drying grayish to light brown; cataphylls 5.5–10 cm long, medium green, deciduous. Leaves erect; petioles 6–20.5 cm long, 2–4 mm in diameter (dry), obtusely C-shaped, medium green, sometimes pale striate, drying dark gray to dark brown; geniculum slightly swollen and darker than petiole, drying darker; blades coriaceous to subcoriaceous, usually narrowly obovate, sometimes elliptic, acuminate at apex, acute to cuneate at base, 18.5–40 cm long, 4.5–12 cm wide, (2.7) 3.5–4.1 (5.5) times longer than wide, (1.6) 2.3–3.9 (4.3) times longer than petiole, broadest usually beyond middle, upper surface glossy, dark green, with numerous short white raphides (visible under 10 magnification), drying semi glossy and dark brown, lower surface glossy, paler than above in life and dry; major veins drying concolorous above and below, barely raised above, raised below; midrib convex to round-raised, slightly paler on both surfaces; primary lateral veins 40–48 per side, departing midrib at a 40 –50 degree° angle, straight to collective vein, moderately obscure to barely raised on both surfaces, drying with a stitched appearance; collective vein 3–7 mm from blade margin, originating at base; tertiary veins obscure. Inflorescences erect to spreading; peduncle 15.5–35 cm long, 3–4 mm in diameter (dry), longer than petiole, pale green, drying dark brown, sometimes ribbed or striate; spathe spreading to reflexed, 4–13 cm long, 7–15 mm wide, medium green, often with maroon streaks, tapered; spadix sessile, cylindrical, gradually tapered, 7.5–18 cm long, 4–5 mm in diameter (dry) near base, 2–3 mm in diameter (dry) near apex, light green, drying gray; flowers square, 2–2.8 mm long, 1.7–2.6 mm wide; tepals with numerous short white raphides on the sides; pistils paler than tepals, early-emergent; thecae oval, 0.1–0.2 mm long. Infructescence 7–29.5 cm long; berries early-emergent, green becoming yellow, orange to red-orange at maturity.

Type: Ecuador. Guayas: in silvis ad sinam Guayaquil prope Balao, Sodiro 16 (holotype, B). Anthurium gracillimum Engler, Bot. Jahrb. Syst. XXV. 371. (1898). Syn. nov. Type: Colombia. Valle: Buenaventura, Lehmann 3826 (holotype, B).

Los Ríos: Río Palenque Biological Station, 150--220 m, 0°35'S, 79°22'W, Dodson 5884 (RPSC, SEL, US); Jauneche, 70 m, 1°16'S, 79°42'W, Dodson et al. 8784 (GUAY, MO, SEL); 400 m, 1°40'S, 79°21'W, Cornejo & Bonifaz 4849 (GUAY, MO); 505 m, 1°39'S, 79°19'W, Roponen & Lindström 144 (MO).