Clerodendrum excavatum De Wildeman (1909: 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 : 12-14

8. Clerodendrum excavatum De Wildeman (1909: 132 & pl. XI; 1910a: 401; 1920b: 167); Moldenke (1986a: 355); Lebrun & Stork (1997: 511); Pollard (2022: 24).

Type:— D.R. CONGO. Env. Yambuya, 1906, Solheid 379 (lectotype designated here: BR0000008976116!, BR0000008976130!) .

= Clerodendrum grandifolium G ü rke (1893: 173); Durand & Schinz (1896: 223); Baker (1900: 307); Durand & Durand (1909: 439); Lejoly et al. (2010: 294). Type:—Oberes Kongogebiet [D.R. CONGO], Land der Majakalla am Quango, November 1880, Mechow 530 (holotype: B, not seen), nom. illeg. non Clerodendrum grandifolium Salisb. ( Salisbury 1796: 108) .

= Clerodendrum excavatum var. cuneatum De Wildeman (1909: 132 , pl. XI, Fig 1-3 ) ≡ Clerodendrum grandifolium var. cuneatum (De Wild.) Thomas (1936: 63) , nom. illeg. Type:—D.R. CONGO. Mogandjo, March 1906, M. Laurent 1913 (holotype: BR0000008976154 (leaves)!, BR0000008971128 (flowers)!).

= Clerodendrum excavatum var. rotundatum De Wildeman (1909: 133 , pl. XI Fig 4 ; 1912b: 192; 1920b: 167). Type :—D.R. CONGO. Env. Yambuya, 1906, Solheid 379 (holotype: BR0000008976116!, BR0000008976130!), nom. illeg.

= Clerodendrum globuliflorum Thomas (1936: 99) ; Huber (1963: 443); Lebrun & Stork (1997: 511); Vande weghe et al. (2016: 743). Type:— FERNANDO PO. Nordseite d. Piks v. Sta. Isabel oberhalb Basilé, Wald ü ber der Kakao-Region, Mildbraed 6345 (holotype: B, not seen; iso-: HBG513436).

Shrub 1–3 m high or liana up to 15 m high and 2 cm thick. Twigs papillate when young, up to 2 cm thick when defoliated, hollow, inhabited by ants, with persistent petiole bases straight, 9–12 mm long. Leaf: petiole 2–11 cm, up to 2.5 mm thick, canaliculate, stiff, glabrous; lamina elliptic to obovate-elliptic, (8–)20–31 × (4–) 10–16 cm, base cuneate to obtuse, apex acuminate, glabrous, margin entire to undulate, 5–7 pairs of veins slightly impressed above. Inflorescence axillary on defoliated shoots, capitate, 4–9 cm in diam. (corolla excluded), axis 1–2 cm, sometimes with secondary axes 5 mm. Flower: pedicel 3–15 mm, glabrous; bracteoles narrowly ovate to linear, 4–10 mm long, purplish or violaceous, shortly ciliate; calyx (13–) 18–28 mm long, tube narrow, lobes ovate to ovate-elliptic, (10–)14–21 × (4–) 5–8 mm, acute to acuminate, glabrous, purplish or violaceous, 5-veined, reticulum prominulent, margin smooth or, more rarely, with a few cilia 0.5–1 mm in tip; corolla: tube 100–170 mm, greenish, generally with sessile glands, more rarely with glandular hairs, lobes elliptic ca. 15 mm long, subglabrous and with sessile glands on outer surface, cream, sometimes reddish tinged, stamens protruding 30–35 mm, anther ca. 3 mm long. Fruit: not observed.

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

Distribution elsewhere:— Central African republic, Nigeria, Equatorial Guinea, Gabon, Cameroon.

Habitat:—Rainforest of various types, sciaphilous species; 300–1000 m.

Selection of representative specimens:—D.R. CONGO. Mayombe: s.l., 1909, Deleval s. n. (BR!). Bas-Congo: Région de Kilemfu, s.d., Gillet s. n. (BR!); Kisantu, 20 December 1920, Schouteden 126 (BR!). Kasaï: s. l., 1925, Achten 761 (BR!); Kakenge, November 1937, Gillardin 303 (BR!); Kapanga, July 1933, Overlaet 985 (BR!). Forestier Central: Boyekoli Ebale Congo expedition 601, Gille 269 (BR!); à 20 km de Yalibwa, 17 January 1936, Louis 1035 (BR!). Ubangui-Uele: Bas-Uele, 27 December 1934, De Wulf 522 (BR!); Entre Libenge et Zongo, November 1930, Lebrun 1702 (BR!). Lacs Edouard & Kivu: Territ. Kalehe, Kabishula, 13 March 1954, Christiaensen 397 (BR!).

Lectotypification of Clerodendrum excavatum De Wild. In the protologue, De Wildeman (1909: 132) considered that his new species comprised two varieties, which he referred to as “ var. cuneatum ” and “ var. rotundatum ”, respectively; therefore, one of the two names is illegitimate. Thomas (1936) and Moldenke (1986a) considered “ var. rotundatum ” as representing the type variety and I follow this interpretation here by designating Solheid 379 as the lectotype of Clerodendrum excavatum De Wild. Therefore , Clerodendrum excavatum var. rotundatum De Wild. is illegitimate.

2. Clerodendrum globuliflorum Thomas (1936: 99) is a morphotype with corolla 60 mm long, shorter than the type, and corolla tube densely glandular-pubescent; Pollard (2022) regards it as a synonym. In our territory, the corolla is generally longer and with sessile glands or, more rarely, with sparse glandular hairs.

Figures

FIGURE 1. Clerodendrum baumii (Jernandez 26 and Devred 1998 (BR)). (A) Habit. (B) Leaf tip underside. (C) Portion of corolla tube. Drawing by Hilde Orye, Botanical Garden Meise (©).

FIGURE 2. Clerodendrum capitatum var. pubitubum (Van Meel in de Witte 5368 (BR)). Fruiting calyx. Scale bar is 1 cm. Drawing by Pierre Meerts, Botanical Garden Meise (©).

FIGURE 3. Clerodendrum dewittei. (Thiébaud 339 (BR)). https://www.botanicalcollections.be/specimen/BR0000015681454

FIGURE 4. Clerodendrum fasciculatum. (Lewalle 2080 (BR)). https://www.botanicalcollections.be/specimen/BR0000019278414