Renealmia vermoeseniana Dhetchuvi & Eb.Fisch., 2024

Fischer, Eberhard & Dhetchuvi, Jean-Baptiste M. M., 2024, A revision of the genus Renealmia (Zingiberaceae) in Tropical Africa. I. New species from Central Africa (Cameroon, Rio Muni, Gabon, Democratic Republic of the Congo), and notes on the identity of Renealmia africana, R. congolana, and R. dewevrei, Phytotaxa 674 (1), pp. 55-96 : 86

Renealmia vermoeseniana Dhetchuvi & Eb.Fisch. , sp. nov. ( Figs 26–27 , 33).

Type: —D.R. CONGO. Forestier Central, Maringa-Lopori, April 1907, A. Bruneel s.n. (holotype BR 0000008818706!). Diagnosis: —The new species can be easily recognized by the upper sheaths of the inflorescence bearing a foliar appendage, and the elongate and lax cincinni usually bearing 1 flower (rarely 2–3).

Description: —Perennial herb forming dense clump. Leafy shoots up to 160 cm tall, covered at base with imbricate leafless sheaths. Leaves with sulcate sheaths surrounding stem, venation not anastomosing, with numerous orange hairs between furrows. Petiole 2–3(–5) cm long. Ligule obtuse, up to 1 mm long, densely hairy outside. Lamina narrowly elliptic, progressively attenuate at base and unequally decurrent on apex of petiole, progressively acuminate at apex, acumen c. 1 cm long, about 50 cm long and 8 cm wide, lateral veins visible at both surfaces, more prominent on lower surface. Inflorescence thyrsic, arising at base of leafy shoots, c. 80 cm long; peduncle about 40 cm long, with glabrous sheaths, basal ones ciliate at margin, upper ones with leaf-like appendage of a ligule and a lamina not exceeding 20 cm of length of about 5–10 cm length, ciliate near margin, internodes glabrous. Bracts persistent, weakly coriaceous to hyaline, narrow, pubescent outside, lower ones c. 7.5 cm long, upper ones shorter, with numerous parallel veins; bracteoles hyalines, persistant, tubular; partial inflorescences (cincinni) c. 20, lax and elongate, peduncle 2–5 cm long, with 1 (–3) flowers; pedicels about 15 mm long. Calyx persistent, accrescent in fruit, turbinate, glabrous except for ciliate margin, purple, about 8 mm long, 1 cm long in fruit. Corolla whitish, upper petal rounded, 5 mm long, tinged with mauve, labellum whitish with purple, about 12 mm long, with appendage at side. Stamen with 1 bilocular theca, about 2.5 mm long, with longitudinal dehiscence. Ovary 2–3 × 1–2 mm, pubescent, greenish, style 8 mm long, stigma bilobed. Fruits elliptic, with simple hairs, shining black at maturity, c. 1.2 cm long. Seeds globose-polygonal to irregular, 3 mm in diameter, 5–6 per locule.

Distribution: —Only known from the Congo basin in D.R. Congo, district “Forestier Central”.

Habitat: —Swamp forest, 315– 450 m.

Etymology: —Named after Camille Vermoesen (1882–1922), Belgian botanist and mycologist who already recognized the plant in an annotation on the herbarium sheet as a new species.

Preliminary IUCN conservation assessment: —The new species is widespread in the Forestier Central phytogeographical district of the Flore d’Afrique Centrale. As the species probably tolerates secondary and open forests, no actual threat is observable, the species is preliminarily assessed as Least Concern (LC).

Additional specimens seen (Paratypes): —D.R. CONGO. Forestier Central , à 15 Km au Nord de Yambao, le long de la Lombo, 29 June 1939, J. Louis 15431 (BR0000020218447) ; Riv. Salonga , entre Bofoku et Botoka Ndjoku. Monkoto Parc National, 6 August 1958, C. Évrard 4519 (BR0000020218423) ; Eala , 19 June 1920, L. Pynaert 1454 (BR0000020218386) ; Terr. Bomboma (Ngiri), 28 April 1938, C. Léontovitch 72 (BR0000020218430) ; env. Bikoro. Lac Tumba , December 1920, V.G. Goossens 1562 (BR0000020218416) ; Maringa , environ Coquilhattville (= Mbandaka), June 1907, L. Pynaert 1627 (BR0000020218409) .

Figures

FIGURE 26. Renealmia vermoeseniana. Holotype, BR. Reproduced with permission from BR.

FIGURE 27. Renealmia vermoeseniana. A, B. Leaves. C. Detail of inflorescence. D. Cincinnus showing bract, bracteole, and fruit. E. Fruit.A–C from Bruneel s.n.; D from Léontovich 72. Illustration by E. Fischer. Scale bars: A–E.1 cm.