Rhapis micrantha Beccari (1910: 220)

Henderson, Andrew, 2016, A revision of Rhapis (Arecaceae), Phytotaxa 258 (2), pp. 137-152 : 146

7. Rhapis micrantha Beccari (1910: 220) . Lectotype (designated by Hastings 2003):— VIETNAM. Dong Ban mountains , Kien Khe 19 April 1884, H.-F. Bon 2345 (lectotype P!, isolectotype FI!)

Stems 1.8(1.5–2.0) m long, 0.8(0.7–0.8) cm diameter. Leaf ligules acute, soon disintegrating; petioles 37.0(20.5–73.0) cm long, 2.6(1.8–3.3) mm wide at the apex; abaxial hastula usually complete, a low ridge separating petiole apex from costa; segments 8(5–13) per leaf; central segments lanceolate or elliptic, usually multi-veined, acuminate, the apices oblique, toothed, 26.9(18.0–35.0) cm long, 3.0(2.2–4.2) cm wide at midpoint, free almost to the base, rarely joined at the base, the non-split basal part 0.7(0.1–2.5) cm; lateral segments 23.8(17.0–32.5) cm long, 1.8(1.0–3.6) cm wide at midpoint, the non-split basal part 0.6(0.1–1.7) cm; abaxial surface of segments without scales, not indumentose when first exposed. Inflorescences small to large, with the first branch almost as large as the rest of the inflorescence; prophyll and peduncular bract narrow, tubular, not or scarcely overlapping, the inflorescences exerted apically through the bracts on a curved peduncle; rachis 15.9(10.0–20.0) cm long; rachillae filiform, usually tomentose, especially the staminate ones; proximal rachilla 6.9(3.3–10.7) cm long, 0.7(0.4–1.2) mm wide; staminate and pistillate flowers sessile; staminate and pistillate corollas with poorly developed, inturned apical lobes, these not swollen internally; filaments terete; fruits globose, white, 7.5(6.1–8.5) mm long, 6.8(6.3–7.4) mm diameter, borne on a pedicelliform pistillate corolla.

Distribution and habitat:—Northern Vietnam (Ninh Binh, Thanh Hoa)( Fig. 4 ) in lowland forest on limestone outcrops at 200(100–300) m elevation.

Taxonomic notes:— One specimen (Spire 5929 at P) is labeled from Laos, and apparently from a place called ‘Ko San’. It is determined by Hastings as R. micrantha and appears to represent that species. The locality has not been found on maps or gazetteers. According to Gagnepain (1943), Spire collected around Luang Prabang in Laos.

Figures

FIGURE 4. Distribution maps of Rhapis kebangensis, R. laosensis, R. micrantha, and R. puhuongensis.