Nonatelia racemosa Aubl., PI. Guian. 1: 187. pi. 72. 1775.
Oribasia racemosa (Aubl.) J. F. Gmelin, Syst. Nat. 367. 1791.
Psychotria longistipula Benth. in Hook., Jour. Bot. 3: 227. 1841.
This species is easily distinguished by the usually 5-(rarely 4-)celled fruit, elongate stipular teeth, puberulous lower midrib and lateral nerves, puberulous branches of the inflorescence, disk with five discrete lobes, corolla with elongated, caudate, and corniculate lobes. Flowering specimens are rare in collections. Of all the specimens examined, only four were in flowering stage. The fruits fall very readily from the branches and are easily detached therefrom.
As one of his key characters for separating Nonatelia (based on Nonatelia racemosa Aubl.) from Psychotria, Bremekamp states (Rubiaceae in Pulle, Flora Suriname 4(1): 124. 1934) “stamens inserted near the base of the tube” (for Nonatelia) contrasted with “stamens inserted in the upper half of the tube” (for Psychotria). Careful checking of flowering material reveals this statement to be in error, as dissection shows that the filaments are inserted about midway or slightly higher on the tube, as in other species of Psychotria, and attached about 1 mm above the base of the tube, the tube being 1.5-1.7 mm long, the filaments inserted in the pubescent zone of the tube which terminates just about midway of the corolla tube. Therefore, this character of stamen insertion must be eliminated from a consideration of generic characters for the separation of Nonatelia from Psychotria. In a previous paper (Rec. Trav. Bot. Néerl. 30: 300. 1934), Bremekamp used as one of his characters in separating Nonatelia from Psychotria that of the insertion of the stamens.