Areca ahmadii J.Dransf., Kew Bull. 39: 4 (1984)

Primary tabs

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Borneopresent (World Checklist of Arecaceae)B
Borneo, Sarawak, 1st Division, known only from the type population. (J. Dransfield, The genus Areca (Palmae: Arecoideae) in Borneo. 1984)A

Discussion

  • The interfoliar inflorescence with long peduncle is superficially very like that of A. brachypoda (see below) and A. subacaulis but the uniseriate staminate flowers indicate this species belongs to section Arecella rather than to section Microareca to which A. brachypoda and A. subacaulis belong. It is unlike any other species in the section because of the inflorescence position, but in details of flowers and fruit it conforms to the pattern common in the section. (J. Dransfield, The genus Areca (Palmae: Arecoideae) in Borneo. 1984)A

Diagnosis

  • ad sectionem Arecellam pertinens, haec species mirabilis habitu acaulescenti, inflorescentia interfoliari, pedunculo longissimo distinctissima; superficialiter A. subacauli (Becc.) J. Dransf. et A. brachypodae J. Dransf. sectionis Microarecae similis sed folio pinnato et floribus staminatis uniseriatis distinguibilis. (J. Dransfield, The genus Areca (Palmae: Arecoideae) in Borneo. 1984)A

Biology And Ecology

Etymology

Description

  • Acaulescent, solitary, undergrowth palmlet; stem very short, subterranean or somewhat decumbent c. 8 x 2.5 cm, bearing very close leaf scars and short stilt roots c. 3 mm diam. Leaf sheaths c. 13 cm long, c. 7 cm in basal circum- ference, apparently tardily abscising, scarcely forming a crownshaft, splitting along ? the entire length opposite the petiole, tinged dull purplish brown, longitudinally striate, and bearing scattered brown scales; ligule present but soon disintegrating. Leaf excluding sheath to c. 1 m, often less, with petiole c. 42 x 0.5 cm; leaflets narrow to broad-lanceolate, in the holotype 6 on each side of the rachis, fewer in some plants noted in the field, (1-) 2-4-ribbed, acuminate except for the apical 5-6-ribbed pair with short apical lobing; basal and mid leaf leaflets to 45 x 1.5 cm, apical pair to 30 x 6 cm, some- what sigmoid, the apical lobing to 5 mm deep; lamina glabrous, adaxial surface rich dark green, shining when fresh, abaxial surface paler. Inflores- cence interfoliar; prophyll to 35 x 1.3 cm, flattened, tinged purplish, bearing scattered brown scales; peduncle becoming arcuate, c. 200 x 2 mm, oval in cross section, somewhat increasing in width with age to 3 mm, purplish with scattered brown scales; rachillae 5-8, purplish, crowded at the end of the peduncle, at staminate anthesis c. 60 x 1 mm, increasing as fruit develops to c. 110 x 2.5 mm. Flowers borne in triads only at the very base of the rachilla, usually no more than 1 triad per rachilla, sometimes no triad present, distally the flattened rachillae bearing a single row of pairs or solitary staminate flowers. Staminate flower sessile, greenish in bud, narrow-clavate, to 4 x 1 mm; calyx 1.5 mm, tubular at the base, tipped with 3 triangular lobes, the central line of each lobe somewhat thickened; petals 3, striate, free almost to the base, 3.5 x 1 mm; stamens 6, with anthers to 2 mm, filaments to 1 mm; pistillode absent; pollen white. Pistillate flower in bud 7 x 3-5 mm; sepals 3, imbricate, cucullate, to 7 x 3 mm; petals 3, imbricate to 6 X 2 mm; staminodes absent; ovary strongly trigonous to 4.5 x 1.5 mm. Mature fruit purplish black, fusiform, 4.3 x 1.4 cm, tipped with conspicuous trifid stig- matic remains; mesocarp thin, fleshy; endocarp thin, fibrous. Seed basally attached, narrow obclavate, 22 X 7 mm; endosperm deeply ruminate; embryo basal. (J. Dransfield, The genus Areca (Palmae: Arecoideae) in Borneo. 1984)A