Neobertiera, Wernham, 1917

Delprete, Piero G., 2019, Additional studies in Neobertiera (Rubiaceae, Sipaneeae): a new species from the state of Pará, Brazilian Amazon, and a new combination for a species from French Guiana, Phytotaxa 392 (3), pp. 225-231 : 230

Key to the species of Neobertiera

1. Inflorescence subcapitate (extremely reduced cyme); corolla tube 3–3.2 mm long, lobes ovate, 0.9–1 × 0.5–0.6 mm ( French Guiana) ............................................................................................................................................................................ N. micrantha

- Inflorescence laxly to densely cymose, or glomerulate; corolla tube 4.5–9 mm long, lobes ovate or narrowly oblong, oblong-ovate to oblong-ellipsoid, 3–7 x 1–2.5 mm ..................................................................................................................................................2

2. Inflorescence glomerulate to densely cymose during anthesis, lateral branches cymose, extremely reduced, terminating with glomerules; corolla tube 8–9 mm long ( French Guiana)................................................................................................... N. palustris

- Inflorescence laxly cymose during anthesis, lateral branches dichotomously divided, with one pedicellate flower at the base of each bifurcation, ultimate branches scorpiod (more evident when fully expanded); corolla tube 4–4.5 or 5.5–11 mm long...........3

3. Rachis thin to filiform; corolla lobes 5.5–7.5 mm long ( Guyana) ...................................................................................... N. gracilis

- Rachis stout; corolla lobes 3–5 mm long...........................................................................................................................................4

4. Stipules entire, narrowly triangular; leaf blades broadly ovate, 3.5–4.5 × 1.9–2.5 cm, round to obtuse at base; hypanthium with hairs basally tuberculate; corollas 14–15.5 mm long, with tube 9.5–10.5 mm long, and lobes ovate, 4.5–5 × 2.5–2.7 mm, acute at apex ( Brazil, Pará) .............................................................................................................................................. N. montedouradensis

- Stipules bifid, ovate to broadly ovate; leaf blades narrowly elliptic, lanceolate to narrowly oblong-elliptic, 4–10 × 0.7–2.5 cm, acute-decurrent at base; hypanthium with hairs not basally tuberculate; corollas 7–7.7 mm long, with tube 4–4.5 mm long, and lobes oblong, 3–3.2 × 1.1–1.2 mm, round to obtuse at apex ( Guyana).................................................................... N. pakaraimensis