Renealmia botsimana Eb.Fisch. & Dhetchuvi, 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 : 57-59

Renealmia botsimana Eb.Fisch. & Dhetchuvi , sp. nov. ( Figs 1–2 , 28).

Type: —D.R. CONGO. Forestier Central, Botsima, layon contournant la station, 21 February 1991, M.M. Dhetchuvi 709 (holotype BRLU!).

Diagnosis: —Differs from all African species in the secund inflorescence with 1-flowered cincinni, tubular bracteoles, and oblanceolateelongate fruits (12–20 × 3–6 mm).

Description: —Perennial herb forming dense clump. Leafy shoots c. 100 cm tall, covered at base with imbricate leafless sheaths. Leaves with sulcate sheaths surrounding stem, without reticulately anastomosing venation. Petiole 1.2–4.5 cm long. Ligule obtuse, up to 3 mm long. Lamina oblanceolate, attenuate at base and decurrent along petiole, caudateacuminate at apex, about 34 cm long and 3.9–5.0 cm wide, greyish-green at lower surface, lateral veins visible at both surfaces. Inflorescence thyrsic, arising at base of leafy shoots, 25–40 cm long; peduncle about 20–25 cm long, with up to 6 leafless sheaths of about 5–8 × 1.2 cm, ciliate near margin, internodes glabrous, rachis about ½ of inflorescence, glabrous. Bracts persistent, membranaceous, glabrous, about 1.0– 1.5 cm long; bracteoles persistent, membranaceous, glabrous, tubular, about 5 mm long; partial inflorescences (cincinni) subsessile, with 1 flower; pedicels red-orange, glabrous, about 3–4 mm long, regularly enlarged at apex. Calyx persistent, accrescent in fruit, tubular, glabrous except for ciliate margin, purple, about 3–4 mm, c. 6 mm long in fruit. Corolla and stamen not seen. Ovary 2–3 × 1–2 mm, glabrescent, greenish-yellowish tinged with purple, style c. 8 mm long, stigma bilobed. Fruits elongate, oblanceolate, glabrous, shining black at maturity, 12–20 mm long and 3–6 mm in diameter. Seeds globose-polygonal to irregular, c. 3 mm in diameter, 3–5 per locule.

Distribution: —Only known from the surroundings of Botsima in D.R. Congo.

Habitat: —Swamp forests, 360– 390 m.

Etymology: —Named after the type locality Botsima.

Preliminary IUCN conservation assessment: —With only one site where Renealmia botsimana has been observed, it is not possible to calculate the extent of occurrence (EOO). The area of occupancy (AOO) with 9 km ² meets the criteria of the Critically Endangered category (CR) under sub-criterion B2. One major threat is the deforestation, as the only known locality lies outside a protected area. However, the numerous specimens (16 herbarium sheets collected in 1991) indicates that the species is probably more abundant. It is thus assessed here as Data Deficiency (DD).

Additional specimens examined (Paratypes): —D.R. CONGO. Forestier Central , Botsima, entre village et station de recherches, 23 March 1991, M.M. Dhetchuvi 1017 (BR0000009477742, BRLU) ; Botsima , Concession de recherche, 28 February 1991, M.M. Dhetchuvi 808 (BR0000009475618), M.M. Dhetchuvi 809 (BRLU), M.M. Dhetchuvi 811 (BR0000009475304), M.M. Dhetchuvi 810 (BR0000009475519) ; Botsima , layon limitant la station, 18 February 1991, M.M. Dhetchuvi 550 (BR0000009475700), M.M. Dhetchuvi 553 (BRLU), M.M. Dhetchuvi 807 (BR0000009475502) ; Botsima , Concession Station de Recherche, 28 February 1991, M.M. Dhetchuvi 814 & 817 (BRLU) ; Botsima , riv. Baampome, 15 March 1991, M.M. Dhetchuvi. 942 (BR0000009475601), M.M. Dhetchuvi. 945 (BRLU) ; Botsima , parc, 15 February 1991, M.M. Dhetchuvi 514, 515 & 516 (BRLU) .

Figures

FIGURE 1. Renealmia botsimana. A. Holotype, BRLU. B. Young fruit with bract and bracteole. C. Detail of inflorescence. A, C from Dhetchuvi 709; B from Dhetchuvi 814. Scale bars: A. 5 cm; B, C. 1 cm. Reproduced with permission from BRLU.

FIGURE 2. Renealmia botsimana. A, B. Leaves. C. Detail of infructescence. A–C from Dhetchuvi 709. Illustration by E. Fischer. Scale bars:A, B. 5 cm; C. 5 mm.