Clerodendrum fasciculatum Thomas (1936: 103)

Meerts, Pierre, 2023, The genus Clerodendrum (Lamiaceae) in the flora of Central Africa (D. R. Congo, Rwanda, Burundi), Phytotaxa 594 (1), pp. 1-42 : 14-15

9. Clerodendrum fasciculatum Thomas (1936: 103) ; Moldenke (1980: 225; 1986b: 408); Lebrun & Stork (1997: 511).— Fig. 4 .

Type:— BURUNDI. Busiga de l’Imbo , Parc national de la Kibira [S ü d-Ruanda, Russiga-Gebirge, westhang], 1909, Meyer 1000 (holotype B, not seen; iso-: JE00004313) .

Suffrutex, shrub, or liana, 1–2 m high. Young shoot beige to fulvous-tomentose, becoming glabrous and grey, with pale lenticels; persistent petiole bases occasionally present, ca. 5 mm long. Leaf: petiole 0.5–2.3 cm, thick, beige tomentose; lamina obovate to elliptic, more rarely ovate, 5–17 × 3–9.5 cm, base cuneate to almost rounded, more rarely subcordate, apex obtuse, or rounded, or shortly acuminate, 4–6 veins on either side, somewhat impressed, upper surface dark green, dull to slightly shiny, mostly sparsely pilose, more densely so on main veins, reticulum prominulent, lower surface more or less villose on veins (thin undulate hairs), margin irregularly undulate-crenate, often crispate. Inflorescence at shoot apex or in the axil of leaves or lateral on defoliated twigs, a dense, subcapitate thyrse 10–20(–50) × 20–30(–50) mm (corolla excluded), with 2–3 nodes, branches 2–4(–15) mm, shortly hispid, bracts narrowly elliptic to linear, 1–3 mm long, pubescent; peduncle 1.5–4 cm, thick, stiff, softly pubescent to tomentose. Flower: pedicel 2–4 mm, puberulent to fulvous-tomentose; calyx 3–4.5 mm long, narrowly campanulate, puberulent, shortly hispid to fulvous tomentose, more rarely glabrous, lobes triangular to broadly ovate-triangular, ca. 1 mm long, acute to shortly acuminate, more or less divergent; corolla: tube ca. 15–20 mm, widening at tip, glabrous to sparsely pilose, lobes ca. 5–7 mm long, glabrous or with sessile glands on outer surface; stamen protruding 10–23 mm, anther 1–1.5 mm long. Fruit: ca. 10 × 5 mm, subtended by the cupuliform calyx ca. 6 × 6 mm.

Distribution in Central Africa:— Burundi.

Distribution elsewhere:—Not known elsewhere; endemic of Burundi.

Habitat:—Savannah, fallow field, xerophilous scrub; 800–1500 m.

Selection of representative specimens:— BURUNDI. Lacs Edouard et Kivu: Plaine de la Rusizi, 23 October 1969, Lewalle 3945 (BR!); Buhonga, 17 October 1967, Lewalle 2080 (BR!, MO); Plaine de la Rusizi, 10 September 1980, Reekmans 9419 (BR!, FHI, WAG); Kabezi , 12 May 1982, Reekmans 11171 (BR!, WAG); Entre Usumbura [Bujumbura] et Isare , 21 May 1926, Robyns 2273 (BR!, WAG). Rwanda-Burundi: Bururi, Makamba, 20 October 1977, Reekmans 6543 (BR!, WAG); Parc national de la Kibira, Busiga de l’Imbo (ca. 10 km from Musigati), 1909, Meyer 1000 ( JE).

Notes:—1. C. fasciculatum is a critical taxon. Most of the materials in collections had been misidentified as C. schweinfurthii . The specimens that we refer to C. fasciculatum are variable, occasionally departing from the protologue; in particular, the upper surface of the lamina is often pubescent (protologue: glabrous), the base of the lamina is cuneate to rounded (protologue: cordate) and the inflorescence is lateral or terminal (protologue: terminal). However, the materials examined show a characteristic combination of traits, including tomentose young twigs and petiole, compact inflorescence on a thick peduncle, short calyx, and corolla tube <20 mm. Some specimens with a less congested inflorescence are somewhat intermediate with C. tanganyikense (Ankei 79/056, Symoens 1341). Heine 297, collected in a riparian forest, is somewhat aberrant, being almost glabrous; it could represent a different taxon, but more materials are needed.

2. The species is a new record to Burundi. It was previously recorded from Tanzania in error, probably due to misinterpretation of the type locality by Moldenke (1980: 225). For the location of the type locality, see Meyer (1984).

Figures

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