Calamus divaricatus var. divaricatus

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Borneo present (World Checklist of Arecaceae)B
Known from a single collection from Temburong. Widespread in Sarawak and Sabah, rare in Kalimantan. Endemic to Borneo. (Dransfield, J. 1997: The Rattans of Brunei Darussalam)A

Discussion

  • C. divaricatus var. divaricatus has been recorded from montane forest on Bt. Tudal. In Sabah it seems to be much more a plant of the lowlands. It is immediately distinguishable by the combination of ecirrate leaf, rugose sheaths and divaricate leaflets. On Bukit Batu Patam grows a rattan very similar in texture and leaf sheath armature to C. divaricatus var. divaricatus but the leaflets are not typically divaricate and the bracts in the inflorescence are not minutely spiny. Unfortunately, it is represented by a single collection with dead inflorescences - Melilas, Bt.Batu Patam, Dransfield J. 6586 - and its true identity will remain uncertain until it is recollected (see Fig. 62). (Dransfield, J. 1997: The Rattans of Brunei Darussalam)A

Etymology

  • Widely divergent (Dransfield, J. 1997: The Rattans of Brunei Darussalam)A

Uses

  • None known. (Dransfield, J. 1997: The Rattans of Brunei Darussalam)A

Description

  • Clustering rattan climbing to 15 m, very rarely ± "stemless"; stem without sheaths 5-7.5 mm diam., with sheaths to 20 mm, usually less, internodes to 12 cm. Sheaths bright green armed with short triangular horizontal spines to 5 mm, united by their bases to form low ridges, these interspersed with low ridges bearing minute tooth-like spines, all covered in deciduous grey indumentum; knee conspicuous, armed as the rest of the sheath; ocrea to 5 mm, ridged, irregularly tattering. Flagellum to 1 m. Leaf ecirrate, to c. 1.1 m including the petiole to 15 cm; petiole armed with short spines to 7 mm and minute scattered prickles; leaflets up to c. 17 on each side of the rachis, distant, usually ± reflexed and subopposite in proximal part, strictly opposite and divaricate near the tip, the apical pair often ± reflexed, the longest at the base, to 30 × 2.5 cm, decreasing to 8.5 × 1 cm, ± unarmed, young leaflets tinged pink. Inflorescences to c. 1 m including terminal flagellum, the female usually with only 1 partial inflorescence, the male with 2-3; bracts conspicuous, those subtending partial inflorescences usually splitting neatly to produce a limb, armed with ridges and scattered spines; axis of female partial inflorescence to c. 12 cm, rather robust, scabrid, bearing c. 12 short reflexed rachillae on each side; rachillae to 3 cm bearing densely crowded flowers; male partial inflorescence laxer, to 20 cm with proximal branches also branched further and with all axes scabrid, male flowers densely crowded. Mature fruit top-shaped, to 16 × 10 mm, including the beak to 1 mm, and covered in 16 vertical rows of chestnut brown scales. Seed pointed, c. 8 × 6 mm, irregularly pitted but endosperm homogeneous. (Fig. 61). (Dransfield, J. 1997: The Rattans of Brunei Darussalam)A

Materials Examined

  • TEM: Amo, Bukit Tudal, Davis 461. (Dransfield, J. 1997: The Rattans of Brunei Darussalam)A

Bibliography

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