Icacina A.Juss.

Rio, Cédric Del, Stull, Gregory W. & Franceschi, Dario De, 2020, Survey of the fruits and endocarps of Icacinaceae (Lamiids, Icacinales), European Journal of Taxonomy 645, pp. 1-130 : 26

Genus Icacina A.Juss.

Figs 10.10–10.26, 11

Description

FRUIT. Elliptical, occasionally slightly globose, asymmetrical at the apex, red-brown to black when mature. Epicarp glabrous or yellowish puberulent with small ovoid hairs to papillate hairs, which line the surface, and simple hairs with granular ornamentation or only simple hairs without granular ornamentation; ridged when dry, revealing the underlying reticulum of endocarp ridges. Calyx persistent.

ENDOCARP. Cream, elliptical to obovate in lateral view, globose to lenticular in transverse section. Keel surrounding the endocarp in the plane of symmetry or faintly visible. Apex truncate or acute, always asymmetrical in lateral view; base symmetrical. Outer surface of the endocarp irregularly rugose or ridged, with a diffuse or reticulate pattern of rounded to sharp ridges. Vasculature follows the ridges or rests between rugosities. Endocarp primary vascular bundle positioned outside or within the endocarp wall. Endocarp wall with at least one row of periclinally oriented cells. Locule surface smooth and faintly lacunate.

Key to the genus Icacina

1. Keel surrounding the endocarp clearly visible, ornamentation rugose with numerous mounds ...... 2

– Keel faintly apparent, ornamentation ridged .................................................................................... 3

2. Apex truncate, endocarp length ca 18 mm .......................................... I. oliviformis (Poir.) J.Raynal

– Apex acute, endocarp length ca 25 mm ...................................................................... I. mannii Oliv.

3. Ridges sharp, reticulate ..................................................................................................................... 4

– Ridges rounded, not reticulate ............................................................................ I. guessfeldtii Asch.

4. Ridges up to 430 µm thick, keel faintly apparent, vascular bundle outside the endocarp wall .......... ......................................................................................................................... I. claessensii De Wild.

– Ridges up to 730 µm thick, keel thick, vascular bundle within the endocarp wall ............................ .................................................................................................................................. I. trichanta Oliv.