Isolona linearis Couvreur

Tree to 15 m tall; d.b.h. to 60 cm; bark dark brown to black, smooth; young branches drying black, glabrous, smooth; old branches dark brown to grey, glabrous, striate. Petioles 4-5 mm long, 1.0-1.5 mm in diameter, glabrous, leaf lamina inserted on side, narrowly grooved adaxially. Leaf lamina 14-18(-25) cm long, 5-7(-9) cm wide, length:width ratio 2.3-3.3, narrowly oblong to oblong or narrowly elliptic to elliptic, coriaceous, glabrous, base rounded to narrowly cuneate, apex acuminate, acumen 5-17 mm long; midrib glabrous on both sides; secondary veins 11-13 pairs, uniformly curved upwards, glabrous on both sides. Rhipidia 1-2, on leafy branches. Flowering pedicels (3-)5-10 mm long, 1-1.5 mm in diameter, glabrous. Lower bracts 2-6, ca. 0.5 mm long, ca. 0.5 mm wide, glabrous, margins sparsely covered with short erect hairs. Upper bract inserted basally or subbasally on the pedicel, 1-2 mm long, ca. 1 mm wide, glabrous; margins sparsely covered with short erect hairs. Sepals 2-3 mm long, ca. 3 mm wide, length:width ratio 0.7-1, transversely elliptic to broadly elliptic, base truncate, apex acuminate, green, persistent in fruit; margins sparsely covered with short erect hairs. Corolla green when immature, red at anthesis; tube 4-5 mm long, lobe:tube ratio 2.5-7.5, glabrous, verrucose when dried; lobes 10-30 mm long, 3-4(-8) mm wide, length:width ratio 2.5-7, linear to narrowly elliptic or rarely elliptic, narrowed at base, apex rounded, sparsely covered with short appressed hairs when very young, glabrous at anthesis, papyraceous. Receptacle 3-5 mm in diameter. Stamens ca. 1.1 mm long; connective shield ca. 0.1 mm long, glabrous, those of innermost whorl slightly extended over ovary wall. Ovary ca. 2 mm, ca. 1 mm wide; stigma ca. 2.5 mm in diameter, glabrous. Fruiting pedicels 5-15 mm long, ca. 3 mm in diameter, glabrous. Fruits ca. 5 cm long, 2-3 cm in diameter, length:width ratio 1.5-2.5, irregularly elliptic, apex apiculate, apicule ca. 1 cm long, furrowed, green tinged with white; pericarp 2-3 mm thick. Seeds 10-15 mm long, ca. 5 mm in diameter, transversely ellipsoid; testa smooth, light brown; raphe thickened, dark brown; hilum not seen.