Rhapis vidalii Averyanov, Nguyen Tien Hiep & Phan Ke Loc (2006: 12)

Henderson, Andrew, 2016, A revision of Rhapis (Arecaceae), Phytotaxa 258 (2), pp. 137-152 : 150

11. Rhapis vidalii Averyanov, Nguyen Tien Hiep & Phan Ke Loc (2006: 12) . Type:— VIETNAM. Hoa Binh: Mai Chau district, Van Mai municipality, highway 7, 15 km post, between 20°35’N, 105°02’E and 20°34’N, 105°02’E, 300–350 m, 12 December 2002, D. Harder, N. T. Hiep, L. Averyanov, DKH 8123 (holotype HN n.v., isotype LE n.v.)

Stems 1.1(0.9–1.3) m long, 0.3(0.2–0.3) cm diameter. Leaf sheath fibers coarse, flattened, forming a diagonal mesh, extended into a well-developed ligule; petioles 17.3(11.0–26.5) cm long, 1.0(0.8–1.2) mm wide at the apex; abaxial hastula usually incomplete, part of the petiole continuous with the costa; segments 7(5–9) per leaf; central segments narrowly linear, usually 1–2-veined, acuminate, the apices scarcely toothed, 16.8(14.2–22.0) cm long, 0.7(0.4–1.2) cm wide at midpoint, free almost to the base, the non-split basal part 0.3(0.2–0.7) cm; lateral segments 15.9(13.0–20.5) cm long, 0.6(0.4–1.4) cm wide at midpoint, the non-split basal part 0.3(0.2–0.4) 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 4.4(2.0–6.7) cm long; rachillae filiform, usually tomentose, especially the staminate ones; proximal rachilla 3.0 cm long, 0.3 mm wide; staminate and pistillate flowers pedicellate; staminate and pistillate corollas with poorly developed, inturned apical lobes, these not swollen internally; filaments terete; fruits globose, white, 9.1(8.9–9.3) mm long, 7.4(7.0–7.7) mm diameter, borne on a pedicelliform pistillate corolla.

Distribution and habitat:—Northern Vietnam (Hoa Binh, Thanh Hoa) ( Fig. 5 ) in lowland forest on limestone outcrops at 647(400–800) m elevation.

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

Figures

FIGURE 5. Distribution maps of Rhapis robusta, R. subtilis subsp. subtilis, R. subtilis subsp. siamensis, and R. vidalii.