Calamus convallium J.Dransf., Kew Bull. 36: 800 (1982)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Borneo present (World Checklist of Arecaceae)B
Known from a single collection from Temburong. Otherwise known from scattered localities in Sabah and Sarawak. Endemic. (J. Dransfield, The Rattans of Brunei Darussalam. 1997)A

Discussion

  • C. convallium is an infrequent rattan usually confined to the bottoms of small valleys, growing on small alluvial flats at altitudes up to 1400 m in Sabah, but usually in the lowlands. It is a very odd rattan; the paired concolorous leaflets suggest at first Daemonorops didymophylla but the leaf is subcirrate and there is a flagellum or flagellar vestige. (J. Dransfield, The Rattans of Brunei Darussalam. 1997)A

Etymology

  • Of deep narrow valleys (J. Dransfield, The Rattans of Brunei Darussalam. 1997)A

Uses

  • None known, though the cane appears to be of good quality. (J. Dransfield, The Rattans of Brunei Darussalam. 1997)A

Description

  • Moderate clustering rattan tending to form rather low open thickets, occasionally high climbing to 20 m long; stem without sheaths 10-15 mm diam., with sheaths to 25 mm diam., internodes to 15 cm long. Sheaths dull green, armed with rather sparse brittle black flattened spines to 25 × 5 mm, spine margins conspicuously fringed with hairs, deciduous pale brown scales present between the spines; knee conspicuous, usually unarmed; ocrea scarcely developed. Flagellum absent in juveniles, reaching 1.3 m only in mature stems, sometimes reduced to a short vestige. Leaf curved, conspicuously subcirrate to 1.5 m including petiole to 30 cm, the petiole armed with distant reflexed black spines along the margins; leaflets lanceolate, somewhat acuminate, 12-20 on each side of the rachis, in the proximal part arranged in very distant pairs, strongly divergent within the pairs, less distinctly paired near the tip, the longest leaflets to 40 × 5 cm, those near the tip very much smaller, the smallest c. 4.5 × 0.4 cm; leaflets armed along the margins only, transverse veinlets conspicuous. Male inflorescence to 1.5 m, bearing 5 evenly spaced partial inflorescences to 16 cm, bracts tightly sheathing, armed with scattered spines, the margins fringed with hairs; rachillae conspicuouslyrecurved; male flowers globular. Female inflorescence much shorter than the male with 1-3 short partial inflorescences. Mature fruit ovoid c. 4 × 2.5 cm, with a conical beak and covered in c. 16 vertical rows of chestnut brown scales. Seedling leaf not known. (Fig. 46). (J. Dransfield, The Rattans of Brunei Darussalam. 1997)A

Materials Examined

  • TEM: Amo, Wong 1917. (J. Dransfield, The Rattans of Brunei Darussalam. 1997)A

Bibliography

    A. J. Dransfield, The Rattans of Brunei Darussalam. 1997
    B. World Checklist of Arecaceae