Otiophora includes herbaceous to suffrutescent, somewhat weedy plants with lobed to setaceous stipules and usually with "supernumerary" axillary leaves borne on axillary stems that do not elongate, terminal inflorescences, a calyx with 1 or several enlarged foliaceous lobes, a white to red, purple, or blue salverform corolla with an extremely, almost impossibly slender ("filiform") tube, schiozocarpous fruits with a solitary seed in each mericarp.
The species of Otiophora so far known from Madagascar are also found in East Africa, and Verdcourt (1976) presents detailed descriptions and some illustrations of these. Otiophora pauciflora has been collected more often than Otiophora scabra; these have been confused with some frequency.
Similar slender, often red to blue, salverform corollas are found in Pentanisia, which generally has the calyx loes linear to triangular and all of similar size or unequal with some of them foliaceous, as in Otiophora. These genera differ primarily in their ovary arrangement, with the locules 2-5 and the ovules attached at the apex of each locule and pendulous in Pentanisia, vs. 2(3)-locular with the ovules attached at the base of the ovule and erect in Otiophora.