Bhesa Buch.-Ham. ex Arn.

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution

A small genus of five species from Ceylon to Indo-China and throughout Malesia; a single species in New Guinea: Bhesa archboldiana (Merr. & L.M.Perry) Ding Hou.

Morphology General Habit

Trees to 30 m

Morphology Leaves Stipules

Stipules present, enclosing branch tips, caducous but leaving large scars

Morphology Leaves

Leaves spiral, coriaceous, elliptic to elliptic-oblong, margins entire, midrib and secondary nerves distinct, tertiary veins distinctively scalariform (‘crossbar veins’); petiole thickened at the distal end

Morphology Reproductive morphology Inflorescences

Inflorescences racemose, axillary, solitary or paired

Morphology Reproductive morphology Flowers

Flowers with distinct articulated pedicels, 5-merous, greenish, fragrant; calyx deeply lobed; petals contorted; stamens opposite the calyx lobes, inserted on the disk; anthers dehiscing introrsely (in New Guinea), latrorse or extrorse; disk present fleshy, subentire or lobed, glabrous; ovary superior, free, glabrous (in New Guinea), or with a tuft of hairs at the apex, 2-celled with 2 erect, anatropous ovules in each cell; styles 2, free, filiform, stigma small

Morphology Reproductive morphology Fruits

Fruit a dehiscent capsule ellipsoid (in New Guinea) or 2-lobed, lengthwise dehiscing loculicidally by 2 valves or on one side

Morphology Reproductive morphology Seeds

Seeds 1–2, completely covered by a fleshy orange aril.

Ecology

Usually found in primary forests from the lowlands up to c. 600 m (outside New Guinea to c. 2200 m).

Recognition

The genus can be recognised vegetatively by presence of conspicuous stipules up to 1 cm long, the alternate leaves with entire margins, with very distinctive scalariform tertiary venation, the petiole thickened at the apex; the flowers are quite small with stamens opposite the calyx lobes coming from the disk which is more or less entire and below the superior ovary with two distinct filiform styles. The fruits are reported to be yellow when mature in New Guinea.