Pyrenacantha thomsoniana (Bail.) Byng & Utteridge, 1038

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 : 93

Pyrenacantha thomsoniana (Bail.) Byng & Utteridge

Fig. 30.10–30.18

Material examined

Specimen used for endocarp and fruit description

GABON • 1907; M. Le Testu 1038; P [ MNHN-P-P04494723 ].

Other material

CENTRAL AFRICAN REPUBLIC • Boukoko ; 10 Dec. 1947; Equipe?; P [MNHN-P-P04494725] • Boukoko ; 27 Jan. 1949; Equipe?; P [MNHN-P-P04494720] .

Description FRUIT. Elliptical, accrescent elongate at the apex (representing 4∕5 of the fruit length). Epicarp pilose,

with yellow long and thin hairs. Mesocarp thin when dry. Calyx persistent, separated from the fruit by an elongate gynophore. Length 45–80 mm, width 14–18 mm, thickness 7–12 mm.

ENDOCARP. Brown, elliptical in lateral view, lenticular in transverse section, length ca 14.8 mm, width ca 11.5 mm, thickness ca 6.8 mm. Keel surrounding the endocarp in the plane of symmetry. Apex slightly asymmetrical in lateral view; base rounded, symmetrical. Outer surface of the endocarp pitted and ridged. Pits circular, occasionally elongate, 0.3–0.6 mm in diameter, randomly arranged with 7–12 pits longitudinally and 9–11 pits transversally (ca 74–83 pits per face). Pits associated with elongateflattened tubercles protruding into the locule; tubercles 634–761 µm in length and ca 670 µm in diameter at the base, with ca 20 cells in width. Tubercle cells sclerotic, digitate and not elongate, more or less anticlinal-isodiametric. Ridges rounded and thin, with 5–6 ridges longitudinally; the median ridge runs from the base up to the apex. Ridges delimiting a reticulate pattern enclosing 5–7 areoles. Secondary ridges delimiting small areoles more or less enclosing each pit. Endocarp wall 376–433 µm thick excluding ridges (520–590 µm thick including ridges). Endocarp wall (excluding pits) with three cell layers: outermost layer with 3–6 rows of anticlinally oriented cells, cells 11.9–35.3 µm in length, followed by a layer with 5–9 rows of periclinally oriented cells, cells 9.7–18.6 µm in width; innermost layer with one row of periclinally oriented cells, cells 6.9–9.9 µm in width, lining the locule surface with regularly spaced and rounded papillae; papillae 7.1–11.2 µm (av. 9.1 µm) in diameter, 650–920 papillae per 0.25 mm 2. Locule not lacunate.