Clerodendrum welwitschii Gürke (1893: 174)

Meerts, Pierre, 2023, The genus Clerodendrum (Lamiaceae) in the flora of Central Africa (D. R. Congo, Rwanda, Burundi), Phytotaxa 594 (1), pp. 1-42 : 37

28. Clerodendrum welwitschii Gürke (1893: 174) ; Baker (1900: 308); De Wildeman (1909: 138; 1912b: 91); Thomas (1936: 60); Huber (1963: 443); Lebrun & Stork (1997: 514); Lejoly et al. (2010: 295); Vande weghe et al. (2016: 744); Pollard (2022: 40)

≡ Siphonanthus welwitschii (Gürke) Hiern ( Hiern 1900: 839) .— Fig. 6 .

Type :— ANGOLA. Golungo Alto , Bumba Quibixe, Sept. 1855, Welwitsch 5648 (lectotype designated here: K000192939!, isolecto-: BM000798621 ; COI00005739 ; G00366307; LISU223664 ; P00442392 , PRE0590601-0) .

Shrub or liana, up to 6 m high, 10 cm diam. at base. Stem terete, reddish, fulvous to rusty pubescent, solid, pith regularly interrupted, with thick persistent petiole bases 5–16(–22) mm. Leaf: petiole 1–8(–12) cm, unequal in length at a node; lamina: broadly ovate to ovate-elliptic, 6–21 × 3.5–14 cm, cordate to rounded at base, apex acuminate, 4–5 veins on either side, sightly impressed on upper surface, reticulum dense, prominent or not on upper surface, upper surface hispid (hairs ca. 1 mm), lower surface hispid on veins, pleasantly smelling when crushed, both surfaces often roughish, margin entire or occasionally somewhat undulate or subcrenate. Inflorescence terminal, a dense thyrse, ovoid to pyramidal, 3–15(–20) × 2–7.5(–10) cm, rachis densely pubescent, sometimes glandular, branches 5–25(–40) mm, at a narrow angle with rachis, peduncle 2–10 cm. Flower: pedicel 5–20 mm, densely pubescent, occasionally glandular, bracts linear to narrowly elliptic, 3–5 mm long; calyx funnel-shaped or bell-shaped, yellow-green, 9–15(–20) mm, base broadly obconical, more rarely rounded, lobed over more than half its length, lobes triangular to ovate-triangular, 5–10 × 2–5.5(–7) mm, 3–5-veined, pubescent on both surfaces, occasionally golden gland-dotted; corolla scented, tube 35–45 mm, greenish, sparsely glandular, more densely so near tip, lobes 7–9(–11) mm long, whitish, rose-spotted near throat, with glandular hairs on outer surface; stamens exserted 15–25 mm, anther 1.5–2 mm long. Fruit 9–11 × 8 mm, concealed in persistent calyx.

Distribution in Central Africa:—D.R. Congo.

Distribution elsewhere:— Angola, Central African Republic, Congo, Gabon, Mozambique, Nigeria, Somalia.

Habitat:—Forest fringe, young regrowth, secondary forest, rainforest, generally heliophilous; 300–1000 m.

Selection of representative specimens:—D.R. CONGO. Mayombe: Tshela, September 1952, Flamigni 10424 (BR!); Luki, 4 September 1957, Matton 23 (BR!); Gimbi, 23 August 1948, Toussaint 462 (BR!). Bas-Congo: Ngombe Ndiwu, 12 July 1953, Callens 4151 (BR!); Kisantu, 11 August 1935, Louis 26 (BR!); Kimuenza, 7 June 1967, Pauwels 5026 ( WAG). Kasaï: Entre Kwanga-Wamba, rivière Twana, 30 July 1944, Germain 2498 (BR!); Sangaie (territ. Lusambo), November 1938, Gillardin 469 (BR!); Popokabaka, June 1925, Vanderyst 14816 (BR!). Forestier Central: Eala, 21 October 1937, Couteaux 377 (BR!); Yangambi, May 1938, Gilbert 1126 (BR!, P); Entre Gemena et Karawa, December 1930, Lebrun 1890 (BR!, P, US); Mobwasa, June 1913, Lemaire 341 ( P); Lilanda (W Yangambi), 22 February 1936, Louis 1338 (BR!); Kotili (près de Buta), 11 December 1925, Robyns 1456 ( WAG). Ubangui-Uele: Bodangabo, 19 February 1955, C. Evrard 288 (BR!).

Lectotypification of Clerodendrum welwitschii Gürke . G ü rke (1893) indicated Welwitsch 5648 as the type. This collection is represented by specimens in BM, COI, G, K, LISU, P and PR. All of them match the protologue. I select the specimen in K as the lectotype (K000192939).

Figures

FIGURE 6. Clerodendrum welwitschii (Le Testu 9480 (BR)) (A) Habit. (B) Cyme. (C) Portion of corolla tube. (D) Node and petiole base. (E) Leaf undersurface. Drawing by Hilde Orye, Botanical Garden Meise (©).