Diogenesia oligantha (A. C. Smith) Sleumer, Notes Roy. Bot. Gard. Edinburgh 36(2): 255.  1978.  Eleutherostemon oliganthum A. C. Smith, Mem. New York Bot. Gard. 8(1): 48.  1952.  Type.  Ecuador.  Morona-Santiago:  Cordillera de Cutucú, Río Itzintza, 1070-1130 m, 17 Nov-5 Dec 1944 (fl), Camp E-1230 (holotype, NY, fragment US, photo NY neg. 9898).

        Epiphytic shrub, sometimes scrambling;  stem terete, striate, bark cracking longitudinally, glabrous;  twigs subterete, sharply to obtusely angled, nitid, minutely puberulous, glabrate.  Leaves chartaceous when dry, ovate-lanceolate to elliptic, (4-)5-13 x (1.5-)1.8-5.5 cm, base broadly obtuse or rounded or inconspicuously subcordate, apex narrowed, long-acuminate to 2 cm long, margin narrowly revolute, glabrous on both surfaces but with few, scattered glandular fimbriae beneath;  5-7-plinerved from near the base, midrib thickened and plane to slightly raised in the proximal 1 cm then impressed distally above and raised beneath, lateral nerves arising from 2-3 cm above base, impressed or plane above but ± raised beneath, reticulate veinlets plane above and raised beneath;  petiole subterete, rugulose, 1-2 mm long, obscurely puberulent, glabrate.  Inflorescence with flowers axillary, solitary, with small bracts at base;  pedicel 10-13 mm long, sparsely puberulent;  bracteoles basal, ovate, long-acuminate, ca. 0.3 mm long, glabrate.  Flowers with calyx 2.5-4.2 mm long, moderately to densely short-hispidulous with grayish hairs ca. 0.2 mm long, also with scattered glandular fimbriae;  hypanthium campanulate, 1.5-2.5 mm long;  limb subspreading, shorter than hypanthium, 1-1.7 mm long;  lobes triangular, acute, often minute, 0.5-1 mm long;  sinuses rounded;  corolla thin carnose, cylindric, 9-13 mm long, glabrous, red, the lobes reflexed, deltate, obtuse, to ca. 1 mm long;  stamen shorter than corolla, ca. 9 mm long;  filaments 5-6 mm long, glabrous or sparsely hispidulus distally;  anthers 3.5-5 mm long;  thecae 1.2-2 mm long, the base rounded or obscurely mucronate;  tubules longer than thecae, ca. 2.3-3 mm long, dehiscing through elongate clefts ca. 0.8-1 mm long;  style slightly exserted;  nectariferous disc fleshy, annular-pulvinate, glabrous.  Berry spherical, capped by persistent calyx limb, 8-9 mm diam., sparsely hispidulous.

        Distribution.  Endemic to Ecuador (Morona-Santiago) and known only from four collections;  found in premontane to wet montane forest, at 1070-1433 m altitude.  Rare and endangered.