Pinanga dumetosa

Pinanga (pih-NAHN-gah) dumetosa (doo-meh-TOH-sah)
Bukit Teraja, Brunei Darussalam (Borneo). Photo by Dr. John Dransfield, Royal Botanic Gardens, Kew/Palmweb.
Scientific Classification
Genus: Pinanga (pih-NAHN-gah) Species: dumetosa (doo-meh-TOH-sah)
Synonyms
None set.
Native Continent
Asia
Morphology
Habit: Clustering Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Borneo.

Bukit Teraja, Brunei Darussalam (Borneo). Photo by Dr. John Dransfield, Royal Botanic Gardens, Kew/Palmweb.

Description

Clustering, low, thicket-forming, unarmed, pleonanthic, monoecious palm. Stems suckering at the base, rarely more than 1 m long, frequently decumbent with only the terminal portion and the crownshaft erect, to 1.3 cm diam. just above the node, to 1.6 cm diam. just below the node, with nodes prominent and about 6 cm distant; stem surface dull green, bearing abundant dark reddish-brown, pale buff-edged scales. Crownshaft elongate, to 25 cm long, scarcely swollen, up to 2 cm diam., dull greenish-brown, rather densely covered in reddish-brown scales as the stem, becoming striate on drying; about 7-8 leaves in crown. Whole leaf including the sheath c. 1.5 m long; leaf sheath c. 25 cm long terminating in an irregularly tattering very short ligule; petiole up to c. 75 cm long, 6 mm wide, triangular in cross-section when fresh, diverging from the crownshaft at an acute angle, dull green, covered in scattered reddish-brown scales as on the sheath; leaflets 6-8 on each side of the rachis, diverging at an acute angle, sub- opposite or alternate; lowermost pair of leaflets narrower than the rest, to 37 x 3.5 cm, frequently narrower; mid-leaf leaflets noticeably lanceolate, not sigmoid, ± parallel sided, to 40 x 5 cm, sometimes wider, with up to 5 main ribs; terminal pair diverging only slightly, joined for up to 14 cm, to 35 x 6 cm, lanceolate, cucullate, the apex shortly toothed with teeth corresponding to the main ribs (up to 9 of them); all leaflets somewhat plicate, dull green, same colour on both surfaces, glabrous except for scattered brown scales along the main veins on the lower surface near the leaflet tips; leaflets rarely much narrower and more numerous, but still detectably lanceolate. Inflorescence infrafoliar, erect, remaining so even to fruit maturity, rarely somewhat spreading; prophyll 6.5 x 3 cm, ovate, strongly 2-keeled, cream-coloured when fresh, quickly turning brown; peduncle scarcely exceeding 1 cm, branching to one order to give up to 8 rachillae to 6 cm long, densely grey tomentose when young; triads rather irregularly arranged, spirally below, distichously above, or distichously throughout, or subdistichously throughout. Staminate flowers not caducous, frequently persisting as shrivelled remains at mature fruiting, the whole flower asymmetric, sometimes very shortly pedicellate, usually sessile; calyx very poorly developed, present as a reflexed, bilobed, undulate collar partly fused with the petal bases, the lobes sometimes interlocking round the pistillate flower, the calyx rarely more than 1 mm high; corolla with 3 well- developed triangular lobes 5 x 2 mm, joined shortly below; stamens about 16; filaments 0.5 mm long; anthers 5 x 1.75 mm. Pistillate flower sessile; calyx cup-shaped, 3 mm diam., with 3 low triangular ciliate lobes to 1.25 mm high; corolla with 3 cucullate free ± rounded ciliate petals 2 mm high; ovary rounded, 2 mm diam., tipped with a subtrigonou cristate stigma. Rachillae becoming orange-red at fruit maturity, glabrescent. Mature fruit turning from crimson to purplish-black, fusiform, 15 x 7 mm; epicarp glabrous; mesocarp thinly fleshy; endocarp fibrous; seed with basal embryo and deeply ruminate endosperm. (J. Dransfield. 1980)/Palmweb. Editing by edric.

This is a curious species, probably most closely related to P. brevipes, P. crassipes, P. latisecta and P. angustisecta. All these species, however, are acaulescent. It is interesting to note that, as in P. dumetosa, the triads in P. latisecta also may be either spiral or distichous, and the staminate flowers are persistent (Dransfield 1974). (J. Dransfield. 1980)/Palmweb.