Rhapis puhuongensis Trudgen, Tran Thi Phuong Anh & Henderson (2008: 182)

Henderson, Andrew, 2016, A revision of Rhapis (Arecaceae), Phytotaxa 258 (2), pp. 137-152 : 146-147

8. Rhapis puhuongensis Trudgen, Tran Thi Phuong Anh & Henderson (2008: 182) . Type:— VIETNAM. Nghe An: Quy Hop district, Pu Huong Nature Reserve, behind Reserve office, 300 m, 19°20’N, 105°10’E, 18 March 2007, X. P. Vu, V. D. Nguyen, H. Q. Bui, C. T. Nguyen R. de Kok, T. Utteridge, A. Moore, M. Briggs, M. Trudgen, V. C. Nguyen & D. D. Tran HNK 1748 (holotype HN n.v., isotypes AAU!, K!, NY!, P!)

Stems 1.2 m long, 0.4 cm diameter. Leaf sheath fibers coarse, flattened, forming a diagonal mesh, extended into a well-developed ligule; petioles 14.8(14.0–15.5) cm long, 1.5(1.3–1.5) mm wide at the apex; abaxial hastula usually incomplete, part of the petiole continuous with the costa; segments 15(15–16) per leaf; central segments narrowly linear, usually 1–2-veined, acuminate, the apices scarcely toothed, 13.6(13.2–14.0) cm long, 0.6(0.5–0.7) cm wide at midpoint, joined at the base, the non-split basal part 5.2(4.3–6.0) cm; lateral segments 12.4(12.0.12.7) cm long, 0.6(0.5–0.6) cm wide at midpoint, the non-split basal part 3.4(3.0–3.7) cm; abaxial surface of segments without scales, not indumentose when first exposed. Inflorescences slender, few branched, with the first branch not 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 8.3(7.5–9.0) cm long; rachillae filiform, usually tomentose, especially the staminate ones; proximal rachilla 3.2(3.0–3.5) cm long, 0.3(0.3–0.4) mm wide; staminate and pistillate flowers pedicellate; staminate and pistillate corollas with poorly developed, inturned apical lobes, these not swollen internally; filaments not recorded; fruits color and size not recorded, borne on a pedicelliform pistillate corolla.

Distribution and habitat:— Vietnam (Nghe An)( Fig. 4 ) in lowland forest on limestone soils at 275(250–300) m elevation.

Taxonomic notes:— By its incomplete abaxial hastula, narrow segments, and pedicelliform pistillate corolla, Rhapis puhuongensis appears most similar to R. vidalii . It differs from that species in its segments that are joined at the base.

Figures

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