Chuniophoenix suoitienensis Henderson, 2015

Henderson, Andrew, 2015, A revision of Chuniophoenix (Arecaceae), Phytotaxa 218 (2), pp. 163-170 : 169-170

Chuniophoenix suoitienensis Henderson , sp. nov. ( Figs. 4 & 5 ).

Chuniophoenix suoitienensis differs from C. hainanensis in its 6–7 (versus 20–28) leaf segments and homogeneous (versus ruminate) endosperm, and from C. nana in its larger size and leaf sheaths split below the petiole to give a central cleft, and winged along the proximal margins.

Type: — VIETNAM. Khanh Hoa: Dien Khanh District, Suoi Tien , 12.203N, 109.027E, ca. 50 m, 4 July 2010, A. Henderson & Bui Van Thanh 3659 (holotype, HN!; isotype NY!) .

Stems clustered, 1.8(1.5–2.0) m tall and 1.9(1.8–2.0) cm diameter. Leaf sheaths split below the petiole to give a central cleft, winged along the proximal margins, densely whitish-brown tomentose, the tomentum early deciduous; petioles 51.5(42.0–61.0) cm long, tomentose as the sheaths; leaf blades divided into 6–7 segments, long acuminate at the apices, the central ones 38.0(34.0–42.0) cm long and 5.4(1.7–9.0) cm wide at mid-point, the central ones split again for one half to two thirds their length into 2–3 lobes. Inflorescences length not recorded, branched to 1 order; prophylls length not recorded; peduncles 25(10–40) cm long, covered with tubular peduncular bracts; rachises length not recorded; rachillae 6(1–11), 14.6(10.2–18.0) cm long; staminate and pistillate flowers yellowish, 2 per bracteole; staminate flowers with well-developed stamens and poorly-developed gynoecia; pistillate flowers with vestigial anthers and well-developed gynoecia. Fruits pedicellate, globose 10.0 mm long and 10.1 mm diameter, green (immature); seed surfaces ridged, brain-like; endosperm homogeneous.

Distribution and habitat:—Southern Vietnam (Khanh Hoa) ( Fig. 2 ) in disturbed forest along steep, rocky river margins at ca. 50 m elevation.

Taxonomic notes:— Chuniophoenix suoitienensis appears to be dioecious. Based on notes made at the time of collection of the type specimen, inflorescences of presumed staminate plants have shorter peduncles to 10 cm long, elongate rachises, and 10–11 rachillae, these to 18 cm long. Presumed pistillate plants have longer peduncles 30–40 cm long, shorter rachises, and 3–4 rachillae, these to 15 cm long.

Local names and uses:— la non. No uses recorded.

Additional specimens examined:— VIETNAM. Khanh Hoa: Dien Khanh District, Suoi Tien , 12.203N, 109.027E, ca. 50 m, 20 April 2013, Henderson & Nguyen Quoc Dung 3866 ( FIPI, NY) ; same locality, same date, Henderson & Nguyen Quoc Dung 3868 ( FIPI, NY) .

Figures

FIGURE 2. Distribution maps. A. Chuniophoenix hainanensis (red dots). C. suoitienensis (blue square). B. C. nana (red dots).

FIGURE 4. Chuniophoenix suoitienensis. A. Habit, Suoi Tien, Vietnam (Henderson & Bui Van Thanh 3659). B. Immature fruits, Suoi Tien (Henderson & Bui Van Thanh 3659). C. Staminate flowers, Suoi Tien (Henderson & Nguyen Quoc Dung 3866). D. Pistillate flowers, Suoi Tien (Henderson & Nguyen Quoc Dung 3868) (C, D: images by Dr. Luu Hong Truong).

FIGURE 5. Chuniophoenix suoitienensis. Leaf sheaths and petioles showing leaf sheaths split below the petiole to give a central cleft (lower arrows), and winged along the margins (upper arrow), Suoi Tien, Vietnam (Henderson & Nguyen Quoc Dung 3868). Image by Dr. Luu Hong Truong.