Paederia has several unusual characters in the Rubiaceae. In particular these plants are vines that climb by twining and generally have a foetid or unpleasant odor; the leaves are often cordiform and notably variable in size and shape within a species; the inflorescences of some species have one or a few colored or petaloid leaves associated with the inflorescences ("showbracts", but no petaloid calyx lobes) that apparently function to attract pollinators, in some cases colored by dense pubescence on the upper surface while the lower surface is glabrescent; the corollas of a number of species are fenestrated, or 5-slitted, near the base; the stamens of some species are positioned at different levels in the flower, similarly to those of Amphistemon; and the fruits are drupaceous but dry, with the fruit wall fragmenting at maturity and the two pyrenes flattened and winged around the margins (or subglobose in some species from Asia, Subg. Paederia). These pyrenes are ovate and usually remain attached to a carpophore after the fruit wall is gone.
One or more species of Paederia are found on most continents, with the greatest number of species in southeastern Asia followed by Madagascar. Puff (1991) studied this genus worldwide, with a separate monographic treatment for Madagascar (1991: pp. 293-322) recognizing 10 named species and one incompletely known, un-named species. Exploration in southern Madagascar later documented Puff's un-named species, and it was described by Razafimandimbison & Taylor (2000). Puff separated 3 subgenera, with two of these found in Madagascar, based on morphological characters: Subg. Alatopaederia is found in the Neotropics, Asia, and Madagascar (5 species) and has funnelform corollas, has the stigmas included within the corolla tube, and lacks showbracts; Subg. Lecontea is found in Africa and Madagascar (6 species) and has slenderly cylindrical, relatively long corollas, has the stigmas exserted from the corolla tube, and sometimes has colored showbracts in the inflorescence. However Paederia taolagnaroensis has similar funnelform corollas, relatively short calyx lobes, and glabrous leaves to the other species of Subg. Alatopaederia but has the stigmas exserted from the corolla tube. Puff included the name Paederia grevei as a synonym of Paederia farinosa subsp. farinosa, but in practice the name "Paederia grevei" has been written in herb. on specimens of various species of Paederia so specimens identified with this name are often not Paederia farinosa.
Paederia grandidieri is the most commonly collected species of this genus in Madagascar. Paederia foetida is a species of Asia that is sometimes cultivated and occasionally naturalized (e.g., USA, Mauritius) but is not native to Madagascar. Native plants of Madagascar that were incorrectly identified as this species are now treated as Paederia grandidieri and Paederia mandrarensis. Paederia foetida can be separated by its corollas that are not fenestrate; the names Paederia scandens and Paederia tomentosa are synonyms of Paederia foetida (Puff, 1991).
!CMT, VI 2013