Arenga pinnata (Wurmb) Merr.

Baker, W.J., Barfod, A.S., Cámara-Leret, R., Dowe, J.L., Heatubun, C.D., Petoe, P., Turner, J.H., Zona, S. & Dransfield, J. (2024) Palms of New Guinea. Royal Botanic Gardens, Kew, Richmond. 726 pp.

Morphology General Habit

Massive, single-stemmed tree palm to 20 m

Morphology Stem

Stem ca. 40 cm diam., dying after flowering and fruiting, obscured by old leaf-sheaths and abundant black fibre

Morphology Leaves

Leaf 8–12 in crown, held erect in an untidy shuttlecock, to 8.2 m long; petiole and sheath to 1.6 m long, petiole with abundant grey indumentum, sheath disintegrating into an untidy mass of robust black fibres to 80 cm long; leaflets ca. 150 on each side of leaf rachis, to 120–160 cm long, with jagged tips, arranged irregularly, grouped in 3s in mid section, dark green on upper surface, covered in gleaming, pale indumentum on lower surface, the leaflet base often with a stalk to 2 cm long and an asymetric ear-like lobe to 5 cm long

Morphology Reproductive morphology Inflorescences

Inflorescences branched to 1 order, male and female very similar but female more robust, to 1.5 m long; rachillae to ca. 80 cm long, 10 mm diam. in female, 6 mm diam. in male

Morphology Reproductive morphology Flowers

Male flower bullet-shaped, 8 × 5 mm; stamens ca. 60–120 Female flower spherical, ca. 14 mm diam. Fruit dull dark green, 4–4.5 × 4 cm

Morphology Reproductive morphology Seeds

Seeds 3, 3 × 2.5 cm, with two flattened sides and one curved side, surrounded by irritantcrystals; endosperm homogeneous, embryo lateral.

Distribution

Native distribution unknown, but widely cultivated in South and South-East Asia. Occasionally naturalised near villages particularly in the lowlands of Indonesian New Guinea.

Ecology

Lowland to upland cleared areas.

Vernacular

Aren (Bahasa Indonesia).

Conservation

Least Concern.

Note

Arenga pinnata has been seen in several areas near towns and villages in Indonesian New Guinea but so far appears not to be well represented in herbaria. It is a very familiar palm in Java, Sumatra and Sulawesi, and elsewhere in South-East Asia.

Use

One of the most important multipurpose palms of the Malesian region. Sheath fibre (ijuk) used for thatch, rope and many other purposes, leaves used for temporary packing for fruit, inflorescences tapped for sap, sugar and alcohol production, immature seeds, cooked, eaten as a delicacy.