Calamus parvulus A.J.Hend. & N.Q.Dung, 2010

Henderson, Andrew & Dung, Nguyen Quoc, 2010, Notes on rattans (Arecaceae) from Vietnam, Phytotaxa 8, pp. 25-33 : 30-31

Calamus parvulus A.J.Hend. & N.Q.Dung , sp. nov. ( Plate 3 )

A Calamo tetradactylo ocreis brevibus, pinnis duos sine setosis, differt.

Type:— VIETNAM. Khanh Hoa Province: Khanh Vinh District, Khanh Trung Commune , Suoi Ca Village , 300–400 m, 21 May 2007, N.Q. Dung 2005 (holotype: FIPI!, isotype: NY!) .

Stems clustered, climbing, to 10 m long, 3 mm diam. with sheaths. Leaf sheaths green with scattered brown tomentum, with few, recurved, black-tipped spines to 2 mm long; ocreas scarcely developed, to 3 mm long; knees present; flagella present, to 55 cm long; petioles 2.5–3 cm long, spiny abaxially as the sheaths; rachis 14–19 cm long, with scattered, solitary or paired spines abaxially; cirri absent; pinnae 2 per side of rachis, the basal ones 11.5–14 cm long, 1.7–2 cm wide at the middle, linear-lanceolate, without bristles on veins or margins, the apical ones joined proximally for ca. one third their length. Staminate inflorescences to 0.4 m long, arching, flagellate, branched to 2 orders, with 3–4 partial inflorescences; prophylls 7–9 cm long; partial inflorescence bracts tubular, briefly splitting at the apices, with scattered, recurved spines; rachillae 3– 11 per partial inflorescence, 0.5–2 cm long; staminate flowers 1.5 mm long (immature); calyx 1 mm long, deeply split; corolla 1 mm long, split almost to the base; pistillate inflorescences to 0.25 m long, arching, not flagellate, branched to 2 orders, with 2 partial inflorescences; rachillae 3–6, to 1 cm long; pistillate flowers and fruits not seen.

Distribution and habitat: — Endemic to southern Vietnam in Khanh Hoa Province, in primary, evergreen forest at 300–400 m elevation.

Local names and uses:— may chi. The stems are used in basketry.

Discussion: — Calamus parvulus (named for its small size) differs from all other Calamus in Vietnam by its extremely slender stems, and leaves with only two pinnae per side of the rachis. It appears most similar to C. tetradactylus Hance (1875: 289) from which it differs in its more slender stems (3 versus 10 mm), scarcely developed ocreas (versus well–developed), fewer pinnae per side of the rachis (2 versus 8–13), and pinnae without bristles (versus bristly along the margins).

Figures

PLATE 3. Left. Calamus parvulus—leaves and flagella. Right. Calamus seriatus—leaf sheath spines, longer at sheath apices.