Philodendron macarenense
Epiphytic appressed climber; internodes short, slightly longer than broad, 1 cm long, 8 mm diam.; cataphylls light green with darker stripes, unribbed, deciduous, drying 2.5 cm long, fibrous with fragments of grayish olive-brown epidermis; petioles 7.3-10.7 cm long, 4 mm diam., spongiose, drying broadly and acutely sulcate, grayish olive-brown; blades narrowly oblong-elliptic, 14.2-18.9 cm long, 3.8-4.3 cm wide (averaging 17 x 4), 3.74-4.40 (averaging 4.12) times longer than broad, broadest at middle, 1.7-1.9 (averaging 1.8) times long as petioles, abruptly acuminate at apex, broadly acute at base, drying papyraceous to subcoriaceous, grayish and matte above, grayish yellow-brown and weakly glossy below; upper surface smooth, densely pale-lineate, areolate upon magnification; lower surface relatively smooth, minutely granular upon magnification; midrib drying flattened, finely ribbed and darker above, narrowly raised, finely ribbed and darker below; primary lateral veins 16-20 pairs, arising at a 50-55° angle near middle, scarcely more prominent than minor veins, drying narrowly convex and concolorous above, narrowly rounded and darker below; minor veins arising from midrib, drying obscure above and moderately visible and distinct below, with weakly raised transverse veins present; laticifers short, pale, relatively visible; basal veins 2 pairs. INFLORESCENCES 1-2 per axil; peduncle 6.5 cm long, 2 mm diam.; spathe 4.3 cm long, 8 mm diam., flattening to 2.3 cm wide, outer blade color white, outer tube color green, resin canals moderately conspicuous and dense in the lower 3/4 of the spathe; spadix 4 cm long; staminate spadix 1.9 cm long, 2 mm diam. at base, 2.2 mm diam. midway, the sterile portion not obvious; pistillate portion 2.1 cm long, 2.6 mm diam. at base, 2-2.2 mm diam. at apex; pistils 1-1.2 mm long, 0.6-0.8 mm diam., style scarcely wider than the stigma, prominently sloping; stigma 0.4-0.5 mm diam., 0.2 mm thick, with 5 pits in a circle around the center, the stigmatic papillae flattening into a thin disk, covering the surface of the stigma; ovary with thin walls ribbed longitudinally between the locules; ovules affixed basally, 1 per locule, 0.4 mm long, borne in a gelatinous envelope, this 0.8 mm long, 0.4 mm diam., funicle 0.2 mm long.
Philodendron macarenense is endemic to Colombia in the Sierra de la Macarena at 1500 m in a Premontane wet forest life zone.