Pyrenacantha acuminata Engl., 2085

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 : 71

Pyrenacantha acuminata Engl.

Fig. 23.10–23.18

Material examined

Specimen used for endocarp and fruit description

CENTRAL AFRICAN REPUBLIC • Boukoko ; 18 Apr. 1951; R. P. Tisserant 2085; P [MNHN- P-P04495460] .

Other material

CAMEROON • 1968; R. Letouzey 9166; P [ MNHN-P-P04495454 ].

COUNTRY UNKNOWN • s. loc.; 18 May 1900; s. col. 1863; P [ MNHN-P-P04495455 ] .

Description

FRUIT. Elliptical, acuminate and accrescent at the apex. Epicarp puberulent, with yellow simple hairs with granular ornamentation, ridged when dry, revealing the underlying endocarp ridges. Mesocarp 192–612 µm thick when dry. Calyx persistent. Length 12–17 mm, width 8–12 mm, thickness 4–8 mm.

ENDOCARP. Brown, elliptical in lateral view, lenticular in transverse section, length ca 11 mm, width ca 8.4 mm, thickness ca 5.5 mm. Keel surrounding the endocarp in the plane of symmetry. Apex slightly asymmetrical and acute in lateral view; base rounded, symmetrical. Outer surface of the endocarp pitted and ridged. Pits circular and thin, ca 0.2–0.3 mm in diameter, randomly arranged with 8–11 pits longitudinally and 8–9 pits transversally (ca 93–106 pits per face). Pits associated with spiny tubercles protruding into the locule; tubercles ca 983–1718 µm in length and 352–456 µm in diameter at the base, with 17–18 cells spanning the width. Tubercle cells sclerotic, digitate and elongate. Ridges rounded and thin, more or less diffuse, faintly apparent, with a prominent median ridge running longitudinally from the base up to the apex. Endocarp wall 243–302 µm thick (excluding pits). Endocarp wall (excluding pits) with three cell layers: outermost layer composed of 1–2 rows of isodiametric to periclinally oriented cells, cells 11.8–20.1 µm in width, middle layer with 9–11 rows of periclinally oriented cells, cells 7.0– 35.6 µm in width; innermost layer with one row of periclinally oriented cells, cells 9.16–17.0 µm in width, lining the locule surface with inflated to papillate cells. Locule not lacunate.