Calamus lateralis A.J.Hend., N.K.Ban & N.Q.Dung, Palms (1999+) 52(4). 2008

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Vietnam present (World Checklist of Arecaceae)A

Discussion

  • In Evans et al. (2002) the specimens cited here will key to Calamus poilanei Conrard. C. poilanei, but differs in its fruits with ruminate (versus homogeneous) endosperm and lateral (versus basal) embryo. Ruminate endosperm and a lateral embryo is an unusual combination in Calamus (Beccari, 1908), and occurs in two Indochinese species placed in Beccari?s Group IX - C. gracilis Roxb. and C. melanacanthus Mart.
    Calamus lateralis presumably belongs in Group IX. It clearly differs from the slender, clustered stemmed C. gracilis, but is more similar to C. melanacanthus. This latter is poorly known, and we have seen only three, incomplete specimens from Tanintharyi in Myanmar, all of them lacking leaf sheaths and notes on stem branching. It is unlikely on biogeographic grounds that the two populations represent the same species, there being no precedent in palms for a species being disjunct between coastal Tanintharyi in Myanmar and southern Vietnam and adjacent Cambodia (with the subspecific exception of Calamus bousigonii, with subsp. smitinandii J. Dransf., in Peninsular Thailand, and subsp. bousigonii in Cambodia, southeast Thailand, and central and southern Vietnam). Nevertheless, judging solely from the incomplete specimens of C. melanacathus, Calamus lateralis differs in its longer apical pinna (27 cm versus 4 cm), longer bristles on the adaxial pinnae surfaces (1 cm versus 0.3 cm), and in its floral bracteoles (raised and forming an almost pedicellate base to the fruits versus flat against the rachilla). Calamus lateralis also appears to be a larger palm, with a stem to 70 m long and 4-5.5 cm diameter. Calamus melanacanthus is described on the label of one specimen as having a stem 10 m long and 2.5 cm diameter. (Henderson, A.J., Ban, N.K. & Dung, N.Q., New species of Calamus (Palmae) from Vietnam in Palms (1999+) 52(4). 2008)B

Common Name

  • May xanh, may tu (Vietnam). (Henderson, A.J., Ban, N.K. & Dung, N.Q., New species of Calamus (Palmae) from Vietnam in Palms (1999+) 52(4). 2008)B

Uses

  • Produces one of the best quality, large diameter canes in Vietnam. (Henderson, A.J., Ban, N.K. & Dung, N.Q., New species of Calamus (Palmae) from Vietnam in Palms (1999+) 52(4). 2008)B

Description

  • Stems solitary, to 70 m long, 4-5.5 cm diameter with sheaths. Leaf sheaths closed and tubular, green with dense reddish-brown tomentum initially, without spines or with few, scattered, to 1 cm long spines; knees present, swollen; ocreas obscure; flagella to 5 m long; petioles 19-30 cm long, covered laterally and abaxially with recurved spines to 0.5 cm long; rachis 80-140 cm long, abaxially with spines as the petiole; cirri absent; pinnae 39-51 per side of rachis, 27-39 cm long, 1.5-2.2 cm wide at the middle, lanceolate, regularly arranged and spreading in the same plane, with 1 cm long, brown, yellow-based bristles on the two lateral veins adaxially, sometimes these on the midvein. Staminate inflorescences to 1.7 m long, erect or arching, not flagellate, branched to 3 orders, with to 8 partial inflorescences; prophylls not known; partial inflorescence bracts closely sheathing the main axis, without spines or with a few, recurved spines; rachillae number not known, 2.5 cm long; rachillae bracts 1 mm high, acuminate; floral bracteoles cupular, scarcely lobed; staminate flowers not known, arranged alternately and distichously along the rachillae; pistillate inflorescences to 2.8 m long, including an elongate flagellate extension to 1.8 m long, branched to 2 orders, with 2-5 partial inflorescences; prophylls not known; partial inflorescence bracts splitting laterally; rachillae 21-28, 2-10 cm long; rachillae bracts 1.5 mm high, acuminate; floral bracteoles cupular, scarcely lobed; pistillate flowers not known; fruits 2.5-3.5 cm long, 2 cm diameter, ellipsoid, orange, with the perianth forming a pedicellate base; endosperm ruminate; embryo lateral. (Henderson, A.J., Ban, N.K. & Dung, N.Q., New species of Calamus (Palmae) from Vietnam in Palms (1999+) 52(4). 2008)B

Materials Examined

  • Cambodia and southern Vietnam; lowland rain forest in Vietnam, semi-evergreen forest in Lao, at low elevations. (Henderson, A.J., Ban, N.K. & Dung, N.Q., New species of Calamus (Palmae) from Vietnam in Palms (1999+) 52(4). 2008)B
  • ADDITIONAL SPECIMENS EXAMINED:
    CAMBODIA. MONDULKIRI: Keo Seimaa Distr., near Lapakhe village, O Pam valley, 12°07'N, 106°55'E, 140 m, Evans 96 (K).
    VIETNAM. DONG NAI: Cat Tien National Park, road to north of park headquarters, 11°26'N, 107°23'E, 150 m, 25 May 2007, Henderson et al. 3392 (HN, NY); Cat Tien National Park, trail to Crocodile Lake, 11°26'N, 107°26'E, 150 m, 27 May 2007, Henderson et al. 3398 (HN, NY), Henderson et al. 3399 (HN, NY), Henderson et al. 3400 (HN, NY). (Henderson, A.J., Ban, N.K. & Dung, N.Q., New species of Calamus (Palmae) from Vietnam in Palms (1999+) 52(4). 2008)B

Bibliography

    A. World Checklist of Arecaceae
    B. Henderson, A.J., Ban, N.K. & Dung, N.Q., New species of Calamus (Palmae) from Vietnam in Palms (1999+) 52(4). 2008