Areca chaiana J.Dransf., Kew Bull. 39: 10 (1984)

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Distribution

Map uses TDWG level 3 distributions (https://github.com/tdwg/wgsrpd)
Borneo present (World Checklist of Arecaceae)B
Borneo, Sarawak, 2nd Division, known only from the type (Dransfield, J. 1984: The genus Areca (Palmae: Arecoideae) in Borneo)A

Discussion

  • This curious species is the only member of the genus with a truly spicate inflorescence. So anomalous did the aspect of the palm appear to me in the herbarium, that at first I thought it might be a species of Nenga; however, examination of the flowers and fruit indicates affinity with Areca rather than Nenga and it must be regarded as an aberrant member of section Microareca. (Dransfield, J. 1984: The genus Areca (Palmae: Arecoideae) in Borneo)A

Diagnosis

  • montana ad sectionem Microarecam ut videtur pertinens sed inflorescentia spicata basi triades numerosos con- gestosque ferenti, floribus staminatis complanatis petalis latis statim dis- tinguibilis. (Dransfield, J. 1984: The genus Areca (Palmae: Arecoideae) in Borneo)A

Biology And Ecology

  • Near river bank on slope in open place. Altitude 2000 ft a.s.l. (Dransfield, J. 1984: The genus Areca (Palmae: Arecoideae) in Borneo)A

Description

  • Erect, solitary undergrowth palm. Stem to 2-5 m tall, c. 1-8 cm diam., internodes c. 1.7-2 cm, bearing caducous chocolate brown scales; nodal scars to 4 mm wide. Crownshaft well-defined, light greenish yellow when fresh, drying mid-brown, 27 x 3 cm; leaf sheaths neatly abscising, c. 17 cm long, longitudinally striate, bearing sparse, minute, brown scales; ligule to 3 cm, soon tattering. Leaf pinnate, excluding sheath to 85 cm, including petiole to 15 x 0.3 cm; leaflets about 10 on each side of the rachis, ± close, mostly 1-4 ribbed except for the broader terminal pair which may be 4-8 ribbed, con- colorous, drying greenish brown, proximal leaflets c. 26 x 2.3 cm, mid-leaf leaflets c. 36 x 0.7-2.5 cm, apical pair c. 20 x 2.5-5.5 cm, all acuminate except for apical leaflets which are lobed; minute scales abundant on both surfaces. Inflorescences infrafoliar, simply spicate, to c. 15 cm, arcuate; prophyll winged, (only fragments available); peduncle short c. 20 x 7 mm diam. (at insertion of prophyll) greenish cream when fresh, drying dark, bearing scattered pale scales, proximal c. 1/3 of axis bearing numerous spirally arranged triads, distal portion bearing spirally arranged, solitary or paired staminate flowers, subtended by relatively conspicuous triangular rachilla bracts c. 1 x 1 mm. Staminate flower rather irregularly flattened due to close packing; calyx base stipitate, c. 1 x 0.5 mm, flattened, glabrous; calyx lobes narrow-triangular, c. 2 x 0.5 mm, keeled, the margins minutely ciliate; petals variable, striate c. 9 x 2-3.5 mm; stamens 6, ± epipetalous, filaments c. 2 x 0.2 mm, anthers medifixed, ± divergent at tip and base, c. 5.5 x 0.5 mm, latrorse; pistillode absent. Pistillate flower sessile; sepals 3, ovate, imbricate, cucullate, minutely scaly, striate, c. 8 x 4 mm; petals 3, ovate, imbricate except at the very tip, minutely ciliate at margins, c. 7 X 3 mm; staminodes ?6, minute; ovary ± fusiform, c. 6 x 1.2 mm. Mature fruit ± fusiform and somewhat curved at the tip, c. 30 x 8 mm, with apical stigmatic residue c. 2 mm diam.; pericarp drying dull brown, longitudinally striate; seed basally attached filling a space c. 20 x 6 mm, shrinking to 12 x 5 mm. (Dransfield, J. 1984: The genus Areca (Palmae: Arecoideae) in Borneo)A

Bibliography

    A. Dransfield, J. 1984: The genus Areca (Palmae: Arecoideae) in Borneo
    B. World Checklist of Arecaceae