Synopsis of the genus Vitex (Lamiaceae) in the Democratic Republic of the Congo Author Meerts, Pierre text Plant Ecology and Evolution 2018 2018-11-28 151 3 380 392 http://dx.doi.org/10.5091/plecevo.2018.1504 journal article 10.5091/plecevo.2018.1504 6. Vitex discoideoglandulosa De Wild. ( De Wildeman 1929a: 10 ). – Type : D.R. Congo , Kasaï , entre Lubue et Bena-Makima , May 1910 , Sapin s.n. (lecto-: BR barcode BR 0000018421408, designated here ) . Vitex guerkeana De Wild. ( De Wildeman 1909: 129 ) nom. illeg. non Vitex guerkeana Hiern. Alianescent shrub. Twigs solid, not myrmecophilous, pubescent. Leaflets 5, petiolulate, lamina pubescent on both surfaces. Inflorescence of thyrses, grouped in a terminal panicle. Flowers whitish. Fruit globose, brownish, c. 5 mm , subtended by the patelliform calyx. Distribution – Endemic to D.R. Congo. Note – V. discoideoglandulosa is a member of the complex of V. thyrsiflora-V. buchananii , characterised by a thyrsoid inflorescence, more or less lianescent habit and small globose fruits (section Terminales W.Piep.). Pieper (1928) regarded it as a synonym of V. volkensii Gürke , an East African plant now synonymized with V. buchananii . However, V. discoideoglandulosa lacks the diagnostic trait of V. buchananii , i.e. the golden-yellow glandulose outer fruit layer exfoliating at maturity. It is undoubtedly a distinct species. Table 1 summarizes the differences between the three species. Table 1 – Trait comparison of V. discoideoglandulosa , V. thyrsiflora and V. buchananii in D.R. Congo.

V. discoideoglandulosa	V. thyrsiflora	V. buchananii
Young branches	persistently pubescent, soon terete, solid, not myrmecophilous	puberulent, soon glabrescent, persistently quadrangular, hollow, myrmecophilous	persistently pubescent, soon terete, solid, not myrmecophilous
Leaflets	pubescent on both surfaces	glabrous to puberulent on nerves; upper surface scabrid	pubescent on both surfaces
Fruit	brown, without outer layer	brown, without outer layer	with golden-yellow glandular outer layer
Fruiting calyx	patelliform	patelliform	cupuliform, clasping fruit base

Lectotypification of Vitex discoideoglandulosa De Wild. De Wildeman (1929a) cited six syntypes ( Claessens s.n., Gillet 1973, Gillet s.n. (coll. 1901), Gillet s.n. (coll. 1902), Gillet s.n. (coll. 1926), Sapin s.n.), corresponding to six sheets in BR. The only specimen with fruits is selected as the lectotype , because the characters of the fruits are discriminant with respect to V. buchananii .