Renealmia tenuispica 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 : 83-86

Renealmia tenuispica Eb.Fisch. & Dhetchuvi , sp. nov. ( Figs 24–25 , 32 ).

Type: — CAMEROON. Environs d’Ebodje, 40 km S de Kribi, 7 December 1979, B. Sabatié 460 (holotype P).

Diagnosis: —The new species differs from all African species in the narrow and spike-like inflorescence with 1-flowered sessile cincinni without peduncle, the cup-shaped bracteoles, the absence of a pedicel, and the caducous calyx.

Description: —Perennial herb forming dense clump. Leafy shoots 30 cm tall, covered at base with imbricate leafless sheaths. Leaves with sulcate sheaths surrounding stem, without reticulately anastomosing venation. Petiole c. 3.5 cm long. Ligule obtuse, up to 1.5–2.0 mm long. Lamina herbaceous, obovate to lanceolate, attenuate at base, caudateacuminate at apex, about 19–20 cm long and c. 5.5 cm wide, lateral veins visible at both surfaces. Inflorescence thyrsic, narrow, arising at base of leafy shoots, 22 cm long; peduncle about 12 cm long, with up to 3–4 leafless glabrous sheaths of about 1.5–2.5 × 0.5 cm and long internodes of 3–4 cm, rachis about 2/3 of inflorescence, glabrous, red. Bracts persistent, membranaceous, glabrous, about 2–3 mm long and 1 mm wide; bracteoles persistent, membranaceous, glabrous, cup-shaped, about 1 mm long and 0.5 mm wide; partial inflorescences (cincinni) sessile, without peduncle, with 1 flower; pedicels lacking. Calyx caducous, tubular, glabrous, purple, 4 mm long, 2 mm wide at apex. Corolla white with pink, upper petal rounded, 2 mm long, tinged with mauve, labellum white with pink, about 2.0– 2.5 mm long. Stamen with 1 bilocular theca, about 1 mm long. Ovary c. 2 × 1 mm, glabrous, green tinged with purple, style c. 2 mm long, stigma bilobed. Fruits not known.

Distribution: —Only known from Ebodje in coastal Cameroon.

Habitat: —In dense rainforest, 20– 30 m.

Etymology: —Named after the long and thin thyrsic spike-like inflorescence with sessile cincinni.

Preliminary IUCN conservation assessment: —With only one site where Renealmia tenuispica 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 deforestation, and the only known locality lies outside a protected area. There is only herbarium sheet collected in 1979, which indicate that it is rare. The species is thus assessed here as Critically Endangered (CR B2).

Figures

FIGURE 24. Renealmia tenuispica. A. Holotype, P, habit. B, C. Detail of inflorescence. Scale bars:A. 5 cm; B, C. 5 mm.All from Sabatié 460. Reproduced with permission from P.

FIGURE 25. Renealmia tenuispica. A. Leaf.B. Detail of inflorescence. C. Detail of leaf.A–C from Sabatié 460. Illustration by E. Fischer. Scale bars:A. 5 cm; B. 5 mm; C. 1 cm.

FIGURE 32. Distribution of Renealmia tenuispica.