Description of the plant
Betel nut is a slender, single-trunked, monoecious palm with a prominent crown shaft.
The palm reaches a mature height of 10–20 m (33–66 ft) (exceptionally up to 30 m [100 ft]), with a trunk 25–40 cm (10–16 in) in diameter. Typhoons and tropical storms usually prevent the trees from reaching their maximum height. The canopy is typically 2.5–3 m (8–10 ft) in diameter and consists of 8–12 fronds.
Flowers are unisexual, with both male (=staminate) and female (=pistillate) flowers borne in the same inflorescence.
Inflorescences are crowded, much-branched panicles borne below the leaves. Each terminal branch has a few female flowers borne at the base and numerous male flowers extending from there out to the branch tip. Flowers of both sexes have six tepals, are stalkless (=sessile), creamy-white, fragrant; male flowers are minute, deciduous, have six stamens, arrowhead-shaped anthers, rudimentary ovary; female flowers are larger (1.2–2 cm [0.5–0.8 in] long), with six small sterile stamens and a three-celled ovary bearing a triangular stigma with three points at the apex. The male flowers open for a few hours, shedding pollen most in the morning; bees and other insects collect this. The average male flowering period is 2-4 weeks; after this the stigmas in female flowers become receptive for 3-4 days. The sweet-scented male flowers are visited by bees and other insects for nectar, but insects have not been observed visiting the female flowers. It is thought that most of the flowers are wind pollinated
Fronds are even-pinnately compound, 1–1.5 m (3.3–5 ft) long; pinnae (leaflets) 30–50, lanceolate, 30–70 x 3–7 cm (12–28 x 1.2–2.8 in), longest near middle of frond; frond base sheathing, encircling trunk and forming a green crown shaft, ca. 55 x 15 cm (22 x 6 in).
A fibrous, ovoid drupe, 5–10 x 3–5 cm (2–4 x 1.2–2 in), yellow to orange or red when ripe; pericarp fibrous, ca. 6 mm thick. Seed usually 1, ovoid, globose, or ellipsoidal, 3–4 x 2–4 cm (1.2–1.6 x 0.8–1.6 in), base sometimes flattened; endosperm ruminate (with hard reddish tissue from inner integument extending horizontally into pale brown endosperm); embryo conical, located at seed base.