Clerodendrum schweinfurthii Gürke (1893: 177)

Meerts, Pierre, 2023, The genus Clerodendrum (Lamiaceae) in the flora of Central Africa (D. R. Congo, Rwanda, Burundi), Phytotaxa 594 (1), pp. 1-42 : 26-27

20. Clerodendrum schweinfurthii Gürke (1893: 177) ; Durand & Schinz (1896: 223); Baker (1900: 296); Durand & Durand (1909: 440); De Wildeman (1905: 310; 1910b: 255; 1912b: 91; 1920b: 174; 1922: 267); Robyns (1947: 144); Huber (1963: 443); Verdcourt (1992: 112); Lebrun & Stork (1997: 513); Lejoly et al. (2010: 295); Pollard (2022: 33).

Type:— SOUTH SUDAN. Lande der Niamniam, 17 March 1870, Schweinfurth 3224/3021 (lectotype designated by Thomas (1936): K000192900) .

= Clerodendrum bakeri Gürke (1893: 175) ; Baker (1900: 296); Durand & Durand (1909: 438); Prain (1913: t. 8474); De Wildeman (1920b: 165) ≡ Clerodendrum schweinfurthii var. bakeri (Gürke) Thomas (1936: 71) ; Moldenke (1980: 219) ≡ Clerodendrum congense Baker (1892: 127) nom. illeg. non Clerodendrum congense Engler (1886: 65) . Type:—D.R. CONGO. Stanley Pool, September 1893, H. H. Johnston (holotype: K000192853).

= Clerodendrum longitubum De Wildeman & Durand (in Durand & De Wildeman 1900: 74); Baker (1900: 517); De Wildeman (1905: 310; 1912b: 91, 200); Durand & Durand (1909: 439) ≡ Clerodendrum schweinfurthii var. longitubum (De Wild.) Thomas (1936: 71) ; Lewalle (1972: 128); Moldenke (1980: 219). Type:—D.R. CONGO. Kisantu, 1899, Gillet 100 (holotype: BR0000008978578!).

Small liana, often straggling, or shrub 0.75–3(–7) m high. Stem sparsely spreading pubescent to subglabrous, solid; old stems up to 15 mm diam., striate, lenticellate; persistent petioles bases 7–10(–15) mm. Leaf: petiole 0.3–1.2(–2.6) cm, shortly hispid, rarely glabrous, wrinkled; lamina obovate to elliptic, more rarely ovate, 8–22 × 4–12 cm, base cuneate, more rarely obtuse-rounded, apex acuminate, 7–9 veins on either side, upper surface dull, glabrous, reticulum prominent, lower surface glabrous except for papillate to sparsely hispid mid-vein, margin entire, or undulate or coarsely crenate. Inflorescence lateral on old defoliated shoots often near the ground, rarely terminal, a condensed hemispheric thyrse 2–4 × 2.5–5 cm (corolla excluded), rarely with a pair of branches lower on peduncle, rachis 1–2 cm, with 2–3 nodes, branches ca. 5 mm, pubescent to subglabrous, peduncle 4–22(–30) cm, stiff, often lignified, papillate, puberulent or pubescent, bracts linear, ca. 5 mm long, pubescent. Flower: pedicel 1–5 mm, glabrous to puberulous, bracteoles filiform, 1–2 mm; calyx campanulate, 3.5–4.5(–5) mm long, glabrous or puberulous, lobes triangular, 1– 1.5 mm long; corolla white to creamy-white, bad-smelling, tube 25–35 mm, glabrous, lobes 5–8 mm long; stamens exserted 10–15(–20) mm, anther ca. 1.5 mm long. Fruit: 10 × 8 mm, dark green, subtended by the cupuliform, white, fleshy, calyx 4–8 × 6–10 mm; seeds with orange arilla.

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

Distribution elsewhere:— Angola, Cameroon, Central African Republic, Congo, Gabon, Ivory Coast, Sierra Leone, Sudan, Tanzania, Uganda.

Habitat:—Rainforest (in particular Piptadeniastro-Celtidetum mildbraedii), riparian forest, seasonally flooded forest; 200–1420 m.

Selection of representative specimens:—D.R. CONGO. Bas-Congo: Kindompolo, 13 August 1902, Cabra & Michel 34 (BR!); Territ. Nsele, Buma, 1 June 1980, Nkunga in Pauwels 6363 ( WAG); Nyanga, April 1932, Vanderyst 29149 (BR!). Kasai: Rives du Kwango, 2 August 1944, Germain 2581 (BR!); Kikwit, 10 August 1991, Masens 995 (BR!, WAG); Hemptinne, s.d., Vanderyst 23654 (BR!). Bas-Katanga: Kamunza, September 1957, Schmitz 5805 (BR!); Merode, s.d., Vanderyst 23133 (BR!). Forestier Central: Environs de Coquilhatville [Mbandaka], August 1930, Lebrun 1167 (BR!, P); Yangambi, Ile Esali, 31 December 1935, Louis 922 (BR!); Yangambi, Ile Tukuku, 3 August 1938, Louis 10683 (BR!); Environs de Coquilhatville [Mbandaka], 15 September 1925, Robyns 577 (BR!). Ubangui-Uele: Parc National de la Garamba, 23 December 1949, Demoulin 8 (BR!); Parc National de la Garamba, 18 December 1951, De Saeger 1571 (BR!); Env. Amadi, 14 December 1905, Seret 356 (BR!). Lac Albert: Irumu, 4 March 1914, Bequaert 2707 (BR!). Lacs Edouard et Kivu: près de Mutsora, 25 February 1954, de Witte 9877 (BR!); Katamangu, 15 February 1955, de Witte 11864 (BR!, WAG); territ. Beni, Matwanga, 5 January 1955, de Witte 11819 ( WAG). Haut-Katanga : Plateau de Muhila, Kansimba, 5 October 1986, Kisimba & Muzinga 1 (BR!).— BURUNDI. Rwanda-Burundi: Kigwena, 22 October 1976, Reekmans 5484 (BR!); Mosso-Ruyigi, 17 September 1951, Michel & Reed 390 (BR!).

Note:—This species has sometimes been confounded with forms of C. silvanum with a capitate inflorescence; C. schweinfurthii is easily distinguished by its longer corolla tube and shorter calyx. 2. A form with glabrous petiole has been described as C. schweinfurthii var. bakeri (G ü rke) Thomas, but it is not recognized here.

Remaining syntypes of Clerodendrum schweinfurthii Gürke :— BURUNDI [Seengebiet]. Ihangiro , 10 November 1890, Stuhlmann 897 (B†); D.R. CONGO, Undussuma, 1050 m, July 1891, Stuhlmann 2596 (B†);—D.R. CONGO, an der Ituri-Fähre, 900 m, 20 August 1891, Stuhlmann 2632 (B†); Lendu-Plateau, 1100 m, 17 September 1891, Stuhlmann 2701 (B†).