Vadensea, Jongkind & O. Lachenaud, 2019

Jongkind, Carel C. H. & Lachenaud, Olivier, 2019, Vadensea (Icacinaceae), a new genus to accommodate continental African species of Desmostachys, Phytotaxa 405 (5), pp. 237-247 : 240

Key of the species of Vadensea

1. Flowers 4-merous, with free petals; corolla glabrous outside; ovary and fruit glabrous; inflorescence an elongate spike with flowers regularly spaced; rachis pubescent in two rows, hairs not denser around the base of the flowers than elsewhere ( Nigeria to Gabon) ............................................................................................................................................................................. V. tenuifolia

- Flowers 5-merous, with petals more or less connate at base; corolla pubescent outside; ovary densely hairy, with some scattered hairs persistent on the fruit; inflorescence spicate to glomeruliform (or sometimes shortly branched in V. oblongifolia ) with flowers arranged in irregular clusters; rachis pubescent all around, with hairs denser around the insertion of the flowers...........................2

2. Corolla small, 3–4 mm long, the tube <2 mm long; fruits small, 11–15 × 6–10 mm when dry; inflorescences very variable, elongate to densely crowded, sometimes branched; leaves more or less papyraceous ( Cameroon to D.R. Congo) .... V. oblongifolia

- Corolla large, 7–10 mm long, the tube 4.5–8.0 mm long; fruits large, 15–25 × 10–18 mm when dry (unknown in V. testui ); inflorescences always elongate spikes; leaves coriaceous.................................................................................................................3

3. Calyx divided almost to the base; disk present, cupular ( Sierra Leone to Ghana)................................................................ V. vogelii

- Calyx with lobes much shorter than the tube; disk absent ( Equatorial Guinea to Congo-Brazzaville) .................................. V. testui