Cephaelis trichocephala (P. & E.) Standi., Field Mus. Publ. Bot. 8: 375. 1931.
Uragoga trichocephala (P. & E.) Kuntze, Rev. Gen. 1: 301. 1891.
The available material examined indicates that this species is herbaceous or subherbaceous, with a stem only 20-30 cm tall rooting at a decumbent base. The Brazilian collection cited probably belongs with this taxon, but has pedunculate heads on peduncles 0.6-1 cm long and stipular teeth 5 mm long.
Although the photo of the type collection from B gives the locality as “Maynas Alto” from Peru, the original description states the locality as from “in ripa montosa fluminis Tocache.” Tocache is located on the upper Río Huallaga in the Dept San Martin, where Poeppig is known to have collected. Poeppig describes the stems as “hirsutie densa, rigida, horizontali tecti,” the leaves as “subtus in nervo hirta,” the stipular teeth as “dense hirsutas, ciliatas partitae, lineas quaturo ad sex longae,” and the axis of the inflorescence as “eyma . . . trichotoma” with bracts “solitariae ad bifurcationes, geminae sub quovis flore,” in all of which respects the Wurdack 2361 and other specimens cited agree. The collection of Klug 3241, cited by Standley under Cephaelis trichocephala (in Rubiaceae of Peru, Field Mus. Publ. Bot. 13: 156. 1936), and the collection of Spruce 3241 pertain to a different taxon, described below, with appressed pubescence of the stems and stipular teeth, and with a non-branched inflorescence.