Clerodendrum rotundifolium Oliver (1875: 132)

Meerts, Pierre, 2023, The genus Clerodendrum (Lamiaceae) in the flora of Central Africa (D. R. Congo, Rwanda, Burundi), Phytotaxa 594 (1), pp. 1-42 : 24-26

19. Clerodendrum rotundifolium Oliver (1875: 132) ; Baker (1900: 308); De Wildeman (1912b: 326); Thomas (1936: 61); Robyns (1947: 143); Lebrun et al. (1948: 117); Malaise (1985: 276); Verdcourt (1992: 99); Lebrun & Stork (1997: 513); Fernandes (2005: 98); Bloesch et al. (2009: 628); Burrows et al. (2018: 846).

Type:— TANZANIA. Bukoba district , Karagué, March 1862, Speke 461 (holotype: K000192885) .

= Clerodendrum guerkei Baker (1900: 308) ; Moldenke (1980: 218). Type:— TANZANIA. [German East Africa, Usambara], Kwa Mshuza, Holst 8908a (holotype: B(?) not seen, iso-: HBG-513445).

= Clerodendrum cavum De Wildeman (1920a: 582) ≡ Siphonanthus cavus De Wildeman (1920b: 164 ; 1922: 259). Type:—D.R. CONGO. Mboga, 12 July 1914, Bequaert 5002 (lectotype designated here: BR0000020442521!; isolecto-: BR0000020442545!; NY00137331 (fragm.); US 02773877).

Suffrutex or shrub, occasionally sarmentose, 0.5– 4 m. Stem terete, hollow, velvety-tomentose, with pale lenticels. Leaves occasionally 3-whorled; petiole: (1–) 3–9 cm, shortly tomentose; lamina broadly ovate to deltoid, 4.5–19 × 4–13 cm, base obtuse, rounded or slightly cordate, apex shortly acuminate, discolorous, upper surface somewhat roughish, shortly pubescent, lower surface hispid-tomentose, especially on veins, 4–7 veins on either side, reticulum prominent on lower surface, margin entire to undulate-crenate. Inflorescence in the axils of leaves, in lax dichasia, 2.5–10 cm long (including peduncle), 5–7(–15)-flowered, the uppermost ones grouped in a loose panicle; bracts filiform to narrowly obovate-elliptic, 5–20 mm long, up to 2 mm wide; axes tomentellous. Flower: pedicel 10–40 mm, densely pubescent; calyx funnel-shaped, 11–20(–23) mm long, tube 2–9 mm, lobes narrowly ovate to triangular, acute to acuminate, (2–) 3–5 mm wide, densely pubescent, occasionally purple tinged; corolla: tube (50–) 70–110 mm, with eglandular and glandular hairs, lobes 10–15 mm long, white to yellowish; stamens exserted 25–30 mm, anther ca. 3 mm long. Fruit ca. 12 × 12 mm, dark olive green, subtended by the persistent chartaceous calyx up to 20 mm.

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

Distribution elsewhere:— Cameroon, Congo, Kenya, Malawi, Mozambique, Sudan, Tanzania, Uganda.

Habitat:—Savannah, shrub savannah, especially Hyparrhenia diplandra-Entada abyssinica savannah and Loudetia arundinacea-Hymenocardia acida savannah; more rarely riparian forest, fallow field, xerophilous scrub; 900–1900 m.

Selection of representative specimens:—D.R. CONGO. Lac Albert: Mboga, 12 July 1914, Bequaert 5002 (BR!); Nioka, 4 June 1952, Liben 317 (BR!). Lacs Edouard et Kivu: Entre Beni et Kasindi, 9 August 1914, Bequaert 5205 (BR!); Rumangabo, Zone Lubero, 13 July 1982, Breyne 4383 (BR!); Kivu, Territ. Katana, 5 December 1953, Christiaensen 269 (BR!); Museya, près d’Ishango, 18 May 1954, de Witte 10209 (BR!); territ. Beni, Lomera, 3 November 1954, de Witte 11348 (BR!, WAG); Plaine au sud du lac Edouard, May-June 1929, Humbert 8233 ( P).— RWANDA. Lacs Edouard et Kivu: Route Kibuye-Cyangugu, à env. 30 km de Kibuye, 6 February 1980, Bridson 330 (BR!, WAG). Rwanda-Burundi: Parc National de l’Akagera , bords du lac Ihema, 1 May 1969, Bouxin & Radoux 397 (BR!); Lugarama, SE Gabiro, 4 December 1944, Germain 2893 (BR!), Parc national de l’Akagera, Plaine Kabalele, January 1938, Lebrun 9756 (BR!, P); Région du Mutara, env. Mimuli, 22 December 1957, Troupin 5629 (BR!, WAG).— BURUNDI. Rwanda-Burundi: Mukarehe, March 1935, Becquet 900 (BR!); Kanyinya près du lac Rugwero, 27 December 1965, Lewalle 148 (BR!, MO); Gitega, Rutonde, 3 March 1968, Lewalle 2915 (BR!, MO); Muyinga, Kobero, 26 August 1980, Ndabaneze 1098 (BR!); Gitega, 2 January 1975, Reekmans 4275 (BR!, WAG).

Lectotypification of Clerodendrum cavum De Wild. De Wildeman (1920a) cited three syntypes, i.e. Bequaert 5002, Bequaert 5205, Bequaert 5534. I select as the lectotype the specimen with the largest leaves (Bequaert 5002, BR0000020442521!), because the protologue ( De Wildeman 1920a: 582) describes leaves as being 18–22 cm long. Remaining syntypes:D.R. CONGO.Entre Beni et Kasindi, 9August1914, Bequaert5205 (syntype:BR0000020442859!, BR0000020442873!, BR0000020442880!); Rutshuru, 4 September 1914, Bequaert5534 (syntype: BR0000008978677! & BR0000008978684!).