Plukenetia sect. Pterococcus (Hassk.) Benth. & Hook., Gen. Pl.

Plukenetia sect. Pterococcus (Hassk.) Benth. & Hook., Gen. Pl. 3, 1: 327. 1880. Pterococcus Hassk. , Flora 25 (2, Bleibl.): 41. 1842, nom. cons., non. Pall. 1773. TYPE: Pterococcus glaberrimus (Hassk.) Hassk. [5 Plukenetia corniculata Sm. ]

Vines, lianas, or perennial herbs, stems slender, twining or sometimes procumbent. Leaf venation palmate, primary veins 3(–5). Inflorescences bisexual racemes (rarely racemose thyrses); pistillate flowers solitary (rarely 2) at basal-most node(s); staminate flowers 1/node (sometimes 1–2/node in reduced condensed cymules). Staminate flowers: receptacle convex, subglobose, or globose; nectaries absent; stamens 8–20, densely packed; filaments conical,, 0.5 mm long; pollen P 5 34–40 m m, E 5 40 –50 m m, tectum foveolate. Pistillate flowers: styles entirely connate into a depressed-globose or stout-cylindrical column, 0.5–1.4 mm long, or;70% connate into a stout-cylindrical column with spreading free style arms, 1.3–1.7 mm long. Fruits 4-lobed capsules, dry, dehiscent, 1.1–2 cm in diam. Seeds broadly lenticular, 5.5–10.5 3 5–8 3 2.5–8 mm (“small” or “medium” sensu Cardinal-McTeague et al. 2019a).

The species in this section are distributed in southern Africa and Southeast Asia.

Discussion —Section Hedraiostylus refers to a strongly supported clade within subclade P5 ( Fig. 1 View FIG ) and includes three species, P. africana and P. procumbens from southern Africa and P. corniculata from Southeast Asia. This section is weakly defined morphologically but appears to be united by short styles, 2 mm long, usually shorter than the length of the ovary (although slightly longer than the ovary in P. procumbens ), staminate flowers with short-conical filaments and lacking nectaries, smaller dry dehiscent fruits, and “small” or “medium” seeds. The southern African species are unique for growing in seasonally dry wooded savannas and have evolved thick rootstocks that facilitate resprouting after fires.