Cryptolepis nigrescens (Wennberg) L.Joubert & Bruyns

Apocynaceae (part 2), David Goyder, Timothy Harris, Siro Masinde, Ulrich Meve, Johan Venter. Flora of Tropical East Africa, 2012

Morphology General Habit

Liana with copious latex.

Morphology Roots

Roots tuberous.

Morphology Stem

Stems twining, 10 m or more long; twigs green to purple, older stems brown, rough, scaly

Morphology Leaves

Leaf petiole 2–5(–10) cm long, purplish; blade mostly elliptic, sometimes broadly ovate to narrowly ovate, (7–)13–14(–16) × (3–)5–8(–11) cm, cuspidate or acuminate, base cordate, glossy, bright green above, pale green beneath, veins pale green to purplish beneath

Morphology Reproductive morphology Inflorescences

Inflorescences 10–30-flowered, pale green, glabrous.

Morphology Reproductive morphology Inflorescences Peduncles

Peduncles 1–4 cm long.

Morphology Reproductive morphology Inflorescences Bracts

Bracts acicular, 1–2 mm long.

Morphology Reproductive morphology Flowers Pedicel

Pedicels 2–5 mm long

Morphology Reproductive morphology Flowers Calyx

Sepals broadly ovate, 1–2 mm long, 2 mm wide

Morphology Reproductive morphology Flowers Corolla

Corolla pale green, creamy green or white outside, glabrous; tube 2–4 mm long, halfway reflexed, partly hispid; lobes elliptic to ovate, rounded, reflexed, 10–12 mm long, 4–5 mm wide, fleshy coriaceous, inside velvety and deep crimson, deep violet or black-violet at base turning brown to dark brown towards apex.

Morphology Reproductive morphology Flowers Corona

Coronal collar borne at corolla inversion; lobes 5–7 mm long, filiform to linear, 2–4-segmented above middle with upper two segments tortuous, rarely undivided, greenish-white, pale green or pale yellow

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens green to brown with white hispid hairs on filaments and backs of anthers.

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Filaments terete, 1–2 mm long.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers narrowly ovate, 3–4 mm long

Morphology Reproductive morphology Flowers Gynoecium Style

Style terete, 1–2 mm long; style-head deltoid, truncate, 3 mm long; translators 2.5–3 mm long

Morphology Reproductive morphology Flowers Gynostegium

Gynostegium exserted from corolla

Morphology Reproductive morphology Fruits

Follicles paired, horizontally divergent, cylindrical-ovoid, 12–21 cm long, 1–2 cm diameter, glabrous

Morphology Reproductive morphology Seeds

Seeds brown, elliptic, 3–4 mm long, warty; coma white, 24–25 mm long

Ecology

Thickets, gallery forest; ± 1100 m

Note

Venter & Verhoeven in S. Afr. Journ. Bot. 62: 27 (1996) stated that Preuss 151 (B†) was the holotype of Periploca preusii K. Schum. This was in effect a lectotypification, as several other collections had been cited in the protologue. Extant duplicates of two of the original syntypes have now surfaced – indeed they were cited by Venter & Verhoeven (1996), but not recognised as syntypes at the time. We therefore propose to overturn the earlier lectotypification, and designate the Kew duplicate of Welwitsch 4232 as the lectotype of this name – duplicates of this collection are distributed in a number of other herbaria. D.J. Goyder & H.J.T. Venter. Verdcourt 3598A, a fruiting specimen from K 7 (Voi Hotel, Teita District), has been determined as this species, but in the absence of flowers its identity is questionable.

Distribution

Flora districts: U4 Range: Across West Africa, Cameroon, Gabon, Equatorial Guinea, Central African Republic, Congo-Kinshasa, Angola