Rhyticaryum racemosum Becc.

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 : 104

Rhyticaryum racemosum Becc.

Fig. 33.10–33.18

Material examined

Specimen used for endocarp and fruit description

NEW GUINEA • 1954; Royen 344 8; L [ L.2293115 ].

Description

FRUIT. Epicarp glabrous; mesocarp 70–200 µm thick when dry. Length 15–18 mm, width 10.0– 13.8 mm, thickness 8–10 mm.

ENDOCARP. Cream, length ca 17.1 mm, width ca 13.3 mm, thickness ca 10 mm. Keel surrounding the endocarp in the plane of symmetry. Apex asymmetrical in lateral view; base rounded, symmetrical. Outer surface of the endocarp ridged, with three longitudinal ridges; the median ridge spanning from the base to the apex. Ridges sharp and thin, with a median channel, delimiting a reticulate pattern enclosing ca 10 irregular areoles, each with freely ending ridgelets more or less branched. Endocarp primary vascular bundle outside the endocarp wall. Endocarp wall 363–391 µm thick excluding ridges (520–686 µm thick including ridges). Endocarp wall with three cell layers: outermost layer with ca 8 rows of anticlinally oriented to isodiametric cells, cells 15.7–28.7 µm in length, followed by a layer with ca 11 rows of periclinally oriented cells, cells 8.1–20.0 µm in width; innermost layer with one row of periclinally oriented cells, cells 5.9–7.4 µm in width, lining the locule surface with regularly spaced and large papillae; papillae 8.0–27.0 µm (av. 16.4 µm) in diameter, ca 790 papillae per 0.25 mm 2.