Vitex madiensis subsp. madiensis Verdcourt (1992: 60)

Meerts, Pierre, 2018, Synopsis of the genus Vitex (Lamiaceae) in the Democratic Republic of the Congo, Plant Ecology and Evolution 151 (3), pp. 380-392 : 387

11a. Vitex madiensis subsp. madiensis Verdcourt (1992: 60) ;

Pauwels (1993: 217); Lebrun & Stork (1997: 525); Sales (2001: 196; 2005: 84); Coates Palgrave & Coates Palgrave (2005: 983); Latham & Konda ku Mbuta (2010: 326); Meerts (2016: 231).

Vitex camporum Büttn. ( Büttner 1890: 35) ; De Wildeman (1903a: 121; 1909: 127; 1910a: 255; 1912a: 467; 1912b: 47, 367; 1921: 164); De Wildeman & Durand (1900: 49); Durand & De Wildeman (1898: 124); Durand & Durand (1909: 436).

– Type: Angola, Welwitsch 5728 (lecto-: BM barcode BM 000839714, designated here ; isolecto-: BM barcode BM 000839714, B †) .

Vitex camporum var. longipedicellata De Wild. ( De Wildeman 1909: 127); De Wildeman (1910b: 400; 1912b: 298). – Type: D.R. Congo, Mayombe, Kwamouth , 25 Oct. 1903, E. & M. Laurent s.n. (lecto-: BR barcode BR 0000018430080, designated here ; isolecto-: BR barcode BR 0000018430097) .

Vitex madiensis var. baumii W.Piep. ( Pieper 1928: 62) ; Moldenke (1956: 455).

– Type: Angola, Quiriri, Baum 821 (holo-: B †) .

Vitex madiensis var. schweinfurthii (Gürke) W.Piep. ( Pieper 1928: 63) ; Moldenke (1956: 458) – Vitex schweinfurthii Gürke ( Gürke 1893: 170) .

– Type: South Soudan, Bahr-El-Ghasal, Seriba Ghattas , 7 Jul. 1869, Schweinfurth 2030 (lecto-: Kbarcode K 000192766, designated here ; isolecto-: B †) .

Vitex madiensis var. typica W.Piep. ( Pieper 1928: 63) ; ( Delevoy 1929: 483); De Wildeman (1929a: 11, 1929b: 105); Devred (1956: 113).

– Type: same as Vitex camporum Büttn.

Vitex madiensis var. glaberrima Moldenke ( Moldenke 1952: 63) .

Type: D.R. Congo, Uele, env. Bambesa , Pittery 819 (holo-: BR barcode BR 0000008906205) .

Asmall tree. Leaves 1–3-foliolate; leaflets coarsely crenate-dentate, smooth above, the middle one long petiolulate. Inflorescence of dichasia, long pedunculate, pedicels with long whitish fine hairs; calyx 2–3 mm, broadly campanulate, broad triangular teeth 0.5–1 mm, with long whitish hairs; corolla whitish-mauve 6–8 mm, stamens included; ovary glabrous. Fruit c. 25–30 mm long.

Distribution – Widespread in tropical Africa.

Notes – Vitex madiensis subsp. madiensis is probably the most polymorphic Vitex taxon in Africa. Many morphotypes have received a formal taxonomic treatment; some of them have been reported in D.R. Congo by Moldenke (1956): V. madiensis var. schweinfurthii (Gürke) W.Piep. (5 leaflets; e.g. de Bergyck 34, Robyns 3018), V. madiensis var. baumii W.Piep. (leaflet margin entire; e.g. Lebrun 6748), V. madiensis var. glaberrima (glabrous in all parts; e.g. Pittery 819). These taxa are not recognized here.

The distribution ranges of V. madiensis subsp. madiensis and subsp. milanjiensis overlap broadly in southern D.R. Congo. Specimens with more or less intermediate characters, possibly of hybrid origin, are occasionally found, especially in savannas of Bas-Congo (e.g. Duvigneaud 252Vi).

Lectotypification of Vitex camporum Büttn. Vitex camporum is based on three syntypes which have all been destroyed in Berlin (Büttner 427 & 428; Welwitsch 5728). Two duplicates of Welwitsch 5728 have been found in BM, and one duplicate of Büttner 427 has been found in K (K barcode K001008451); all the duplicates match the description in the protologue. Welwitsch 5728 is a better specimen and one of the two sheets is thus selected as the lectotype.

Lectotypification of Vitex camporum var. longipedicellata De Wild. De Wildeman cites one collection from Kwamouth by E. & M. Laurent, s.n., which corresponds to two sheets in BR. The sheet with collecting data on the label is chosen as the lectotype.

Lectotypification of Vitex schweinfurthii Gürke. The protologue cites two collections i.e. Schweinfurth 2030 & 2848. These specimens have been destroyed in Berlin. Aduplicate of Schweinfurth 2030 matching the description in the protologue exists in K, and is here selected as the lectotype.