Arecaceae
Calamus

Calamus convallium J.Dransf.

First published in Kew Bull. 36: 800 (1982)
This species is accepted
The native range of this species is Borneo. It is a liana and grows primarily in the wet tropical biome.

Descriptions

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: threatened. Confidence: confident
[AERP]

General 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).
Distribution
Known from a single collection from Temburong. Otherwise known from scattered localities in Sabah and Sarawak. Endemic.
[PW]

Uses

Use
None known, though the cane appears to be of good quality.
[PW]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Palmweb - Palms of the World Online

    • Palmweb 2011. Palmweb: Palms of the World Online. Published on the internet http://www.palmweb.org. Accessed on 21/04/2013
    • Content licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License http://creativecommons.org/licenses/by-nc-sa/3.0