Clerodendrum buchananii ( Roxburgh 1832: 60 ) Walpers (1845: 108)

Meerts, Pierre, 2023, The genus Clerodendrum (Lamiaceae) in the flora of Central Africa (D. R. Congo, Rwanda, Burundi), Phytotaxa 594 (1), pp. 1-42 : 6

3. Clerodendrum buchananii ( Roxburgh 1832: 60) Walpers (1845: 108) ; Lam & Bakhuizen van den Brink (1921: 91); White (1962: 365); Moldenke (1985d: 283); Smith (1991: 211); Fernandes (2005: 93).

Type:— INDIA. 1797, Buchanan s. n. (holotype: K, not seen) .

= Volkameria buchananii Roxb. ( Roxburgh 1832: 60) .

= Clerodendrum speciosissimum auct. non Morren (1836: 322 , pl. 68); Lejoly et al. (2010: 295).

= Clerodendrum fallax sensu De Wild. ( De Wildeman 1912a: 468; 1912b: 132) non Lindl. (1844: t. 19).

Shrub, 1.5–3 m, much branched. Stem quadrangular, shortly pubescent to tomentellous. Leaf: petiole 2–25 cm, reddish, pubescent; lamina broadly ovate, 6–18 × 5–18 cm, deeply cordate at base, acute to obtuse at apex, 4–7 veins on either side, upper surface pubescent, lower surface softly pubescent to tomentose, margin undulate-crenate. Inflorescence paniculiform to corymbiform, 13–19 × 11–15 cm, of axillary cymes grouped at shoot apex, with 5–11(–16) nodes, peduncle of the cymes 2–6 cm, reddish, shortly brownish pubescent, cymes 7–11- flowered, the lowermost one in the axil of a foliaceous bract, the other bracts obovate, ca. 5 × 1 mm. Flower: pedicel 4–10 mm, pubescent; calyx funnel-shaped, 2.5–3 mm long, puberulent and with sessile glands, lobes narrowly triangular, 1.5 mm long, often outwardly recurved at tip, reddish; corolla: tube 12–17 mm, papillate, lobes obovate, 9–12 mm long, papillate and with sessile glands on outer surface; stamens protruding 15–25 mm, anther ca. 3 mm long. Fruit 4-lobed, ca. 5 × 8 mm, blue-black, more or less wrinkled, subtended by the persistent cup-shaped calyx ca. 3 × 8 mm.

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

Distribution elsewhere:—Islands of SE Asia and W Pacific; introduced for ornamental purposes in the tropics worldwide.

Habitat:—Cultivated for ornamental purposes, apparently not yet recorded as a garden escape in Central Africa.

Selection of representative specimens:— D.R. CONGO. Bas-Congo: Jardin agronomique de Kisantu , 27 September 1930, Vanderyst 25748 ( BR!) ; Kasaï: Luluabourg [ Kananga ], s.d., Vanderyst 21298 ( BR!) . Forestier Central: Eala , November 1923, Goossens 4389 ( BR!) ; Kisangani , jardin botanique de la Faculté des sciences, 8 July 1974, Lejoly 5441 ( BR!) , Yangambi , poste de Yaosuka, 30 May 1938, Louis 9578 ( BR!) . Haut-Katanga: Elisabethville [Lubumbashi], 1937, Salésiens 725 ( BR!, WAG) .

Note: — This species has generally been referred to as Clerodendrum speciosissimum . C. buchananii and C. speciossisimum are closely related species native to SE Asia, the former sometimes treated as a variety of the latter ( C. buchananii var. fallax (Lindl.) Bakh. ). See Moldenke (1985d) for a discussion of the relations between C. buchananii and C. speciosissimum . Fernandes (2005) was the first to point out that most if not all African specimens better correspond to C. buchananii , due to the short calyx (2.5–5 mm long, vs. 6–8 mm in C. speciosissimum ) and the smaller corolla (lobes 7–12 mm long, vs. 12–17 mm in C. speciossissimum ). Further investigation is needed to clarify the taxonomy of Asian red-flowered Clerodendrum introduced to Africa.