Type. Shrub 0.7-1.5 m, petals pink, fruit reddish, frequent along moist edge of Sabana Huachapana, Rio Orinoco 30 km above Santa Barbara, Terr. Amazonas, Venezuela, alt. 125 m, 15 Sep 1957, Bassett Maguire, John J. Wurdack, & William M. Keith 41468 (holotype U S 2342579). Paratypes. VENEZUELA, Terr. Amazonas. Rio Orinoco: just west of Santa Barbara at junction of Rios Orinoco and Ventuari, alt. 125 m. Cowan d; Wurdack 32028; Sabana de Atures, alt. 120 m, Llewelyn Williams 15935 (VEN). Rio Ventuari: Sabana de Moyo on south bank of Rio Ventuari 15 km above mouth, alt. 150 m, J. S. Level 33. Edo. Bolivar. Rio Orinoco: morichal 2 km east of river near Cerro Gavilan (Cerro Carichana), alt. 100 m, Wurdack d- Monachino 39937.
Nowhere in T. guianensis or its satellite species (T. spruceana Cogn., T. occidentalis Naud., T. latifolia Naud., T. formicaria Mart.), including the morerecently described taxa discussed by Gleason (Bull. Torrey Club 58: 250-251. 1931) does the above diagnostic combination along with very large spheroidal formicaria occur; setulose hypanthia (the hairs usually gland-tipped) are found in various units. The variability loci in the geographically discontinous rassenkreis are both too involved and incompletely studied for elaboration here (i.e. both time and complexity have me stymied for now).