Rhyticaryum elegans G. Schellenb

Rhyticaryum elegans G.Schellenb. Fig. 31.10���31.17 Material examined Specimen used for endocarp and fruit description MELANESIA ��� ��� Papouasie ��� [Papuasia]; 1908; R. Schlechter 18681; P [MNHN-P-P04513302]. Description FRUIT. Epicarp strigose, with yellow simple hairs with granular ornamentation; mesocarp 50���72 ��m thick when dry. Length 16.3���18.0 mm, width 8.2���9.0 mm, thickness 5���7 mm. ENDOCARP. Brown, length ca 15.2 mm, width ca 7.2 mm, thickness ca 5.8 mm. Keel surrounding the endocarp in the plane of symmetry.Apex acute, asymmetrical in lateral view; base rounded, symmetrical. Outer surface of the endocarp ridged, with 2���4 main longitudinal ridges; the median ridge reaching the point of the base. Ridges rounded and thin, with a median channel, almost diffuse but enclosing ca 6 longitudinal polygonal areoles with freely ending ridgelets. Endocarp possessing a symmetrical pair of pores positioned eccentrically and subapically on the median ridge. Primary vascular bundle positioned outside the endocarp wall. Endocarp wall 174���246 ��m thick excluding ridges (280���370 ��m thick including ridges). Endocarp wall with three cell layers: outermost layer with 0���2 row(s) of isodiametric to anticlinally oriented cells, cells 15.9���23.5 ��m in length; middle layer with 8���10 rows of anticlinally oriented cells, cells 18.0��� 20.9 ��m in length; innermost layer with one row of periclinally oriented cells, cells 6.7���11.0 ��m in width, lining the locule surface with regularly spaced and large papillae; papillae 9.1���20.7 ��m (av. 15.1 ��m) in diameter, 500���900 papillae (av. 637 papillae) per 0.25 mm 2.
Published as part of Rio, C��dric Del, Stull, Gregory W. & Franceschi, Dario De, 2020, Survey of the fruits and endocarps of Icacinaceae (Lamiids, Icacinales), pp. 1-130 in European Journal of Taxonomy 645 on page 98, DOI: 10.5852/ejt.2020.645, http://zenodo.org/record/3829651