Viney epiphyte or arching terrestrial shrub to 2 m tall;  mature stems green becoming reddish-brown, drying brown, subterete, glabrous;  bark thin, cracking into longitudinal strips;  immature branches and twigs of the new growth subterete, glabrous to densely hirsute distally.  Leaves coriaceous, entire, elliptic or ovate-elliptic, (4.5-)8-12(-13.5) x (2.5-)3-7 cm, basally rounded and cordate, apically acuminate, dark green above and paler beneath, drying olive to grayish-brown, glabrous above, sparsely to moderately hirsute beneath along the principal veins, the lower surface also with numerous minute glandular fimbriae;  pinnately veined with 3 pairs of lateral nerves, the vines impressed above and raised beneath causing the leaves to be bullate, proximal 1-2 cm of midrib conspicuously thickened above;  pseudostipules (bud scales) lanceolate, subulate, ca. 3 mm long, hirsute;  petioles terete, rugose, hirsute, becoming glabrous, 5-9 mm long and 2-2.5 mm in diam.  Inflorescence axillary but often appearing terminal, racemose or subcorymbose, 8-17-flowered, the rachis, pedicels, bracteoles, calyx and corolla totally green;  rachis 1-1.5 cm long, subterete, reddish-brown, glabrous or sparsely hirsute, densely glandular fimbriate;  floral bracts linear-lanceolate, 3-9 x ca. 1 mm, hirsute, glandular-fimbriate, conspicuously nerved;  pedicels terete, striate, sparsely hirsute, densely glandular fimbriate, ca. 15 mm long and ca. 1 mm in diam., elongating to 26 mm after anthesis, articulate with the calyx;  bracteoles linear-lanceolate, 5-8 x ca. 0.5 mm, hirsute, glandular-fimbriate.  Flowers with the calyx 7-9 mm long, sparsely to moderately hirsute and glandular fimbriate;  hypanthium cylindric, 10-ribbed, slightly  angled opposite the sinuses, 2-2.5 mm long and 2-3 mm in diam.;  limb campanulate, 5.5-7 mm long including the lobes;  lobes oblong to ovate, acute, 5-6 x 1.7-3 mm, often basally slightly imbricate, conspicuously nerved;  corolla cylindric, 11-12 mm long and 5.5-7.5 mm in diam., sparsely hirsute and glandular-fimbriate especially on the surface of the lobes, the lobes triangular, ca. 3 x 3 mm;  stamens 10, ca. 8 mm long;  filaments distinct, ca. 3 mm long, broadest basally, marginally densely sericeous especially on the connective, translucent when fresh;  anthers ca. 7 mm long, strongly curved inwards at the base;  thecae granular, ca. 3 mm long, orangish-brown when fresh;  tubules ca. 4 mm long, sparsely pilose, dehiscing by laterally oriented apical slits ca. 1.5 mm long, yellowish-brown;  style included, glabrous, 9-10 mm long.  Fruit not seen.

    Distribution.  Endemic to Panama, where it is found in premontane cloud forest.  Rare.