Clerodendrum leucobotrys Breteler, 2005

Breteler, F. J., 2005, Novitates Gabonenses 51. A new Clerodendrum (Lamiaceae, formerly Verbenaceae) from Gabon, Adansonia (3) 27 (2), pp. 317-319 : 319

Clerodendrum leucobotrys Breteler , sp.nov.

Clerodendri formicarum Guerke maxime simile forma staturaque folii, statura floris et corolla actinomorpha, ab eo differt inflorescentiis pendulis conspicue confertim albidis pilosis, floribus pendulis flavis et tubo corollae glanduloso.

TYPUS. — Breteler 15827, Gabon , N of Babylone forestry camp, 0°38’N, 11°E,fl. July 2002 (holo-, WAG; iso-, BR, COI, G, K, LBV, MA, MO, P, PRE).

Lianescent shrub c. 1 m tall; branchlets sparsely pilose, probably becoming hollow. Leaves opposite; petiole subterete, channelled above, 4-11 mm long, articulated at ≤ 4 mm from base, glabrous or very sparsely pilose; lamina papery, glabrous, minutely dark-green to black-dotted beneath, narrowly elliptic, c. 3 times as long as wide, (5-)7-11 × (1.5-) 2.5-3.5 cm, cuneate to slightly rounded at base, acuminate at the apex, the acumen acute, 0.5-1.5 cm long; midrib and the 6-8 pairs of main lateral nerves plane to impressed above, prominent beneath. Inflorescences (sub)terminal, cymose, pendulous, densely villous, the hairs ± flat (in sicco), multicellular, 2- 5 mm long; peduncle 1.5-2.5 cm long; bracts and bracteoles linear-oblanceolate, up to 6 mm long. Flowers pendulous; pedicel 2-4 cm long, villous; calyx ± campanulate, 5-lobed, 2-3 mm long, sparsely villous; tube 1.5-2 mm long; lobes suberect, triangular, ≤ 1 mm long; corolla ± regular, yellow; tube 9-11 mm long, c. 1 mm wide, distinctly widened in lowest 1-1.5 mm, slightly so in upper part above attachment of stamens, glabrous in basal part, glandular-pubescent in the middle part, villous on upper part, glabrous inside; lobes spreading to reflexed, oblong-elliptic, 3-3.5 × 2-2.5 mm, villous outside, glabrous inside; stamens attached on tube at c. 3 mm from mouth, up to 10 mm long, long-exserted, glabrous; anthers 1.5 mm long; pistil c. 15 mm long, glabrous; ovary subglobose, 1 mm long, smooth. Fruits and seeds unknown. — Fig. 1.

HABITAT AND DISTRIBUTION. — Rain forest in NW Gabon. Only once collected at an altitude of c. 200 m.

DISCUSSION. — Describing a new species from

Gabon in the large genus Clerodendrum is not

easy, the more so as a taxonomic treatment of the Central African species has not been undertaken since THOMAS’ s revision (1936), dealing with all the African species. In this revision very little material from Gabon has been cited, although the rich collections made by Klaine and Le Testu were available in the Paris herbarium. This herbarium was not visited by THOMAS nor was any material borrowed from it. Identification of Breteler 15827 with the key to the species in THOMAS’ s revision did not lead to a satisfactory result. The same holds for trying to identify the specimen with the Flora of West Tropical Africa and the Flora of Tropical East Africa. A thorough search at the herbaria of Paris and Wageningen, where the best collections from Gabon are locat- ed, did not reveal any species that fitted Breteler 15827, or any material that matched this collection. Only C. formicarum Gürke shows ± similar leaves and flowers, but is clearly distinguished from C. leucobotrys by the latter’s densely whitehairy inflorescences with pendulous flowers. With the new species C. leucobotrys the number of species from Gabon reaches 20.

Figures

FIG. 1. — Clerodendrum leucobotrys Breteler: A, flowering branch; B, flower; C, flower-bud; D, corolla; E, corolla opened out; F, pistil with ovary cut lengthwise; G, glandular hairs of corolla tube. Breteler 15827. Drawing by H. DE VRIES.