Huberantha Chaowasku

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

Distribution

A genus of at least 27 species from Africa and Madagascar through Asia and Melasia to the Pacific; at least seven species in New Guinea. The genus has been recently described to account for one of the distinct groups in the variable genus Polyalthia (see notes below regarding differences between the genera).

Morphology General Habit

Shrubs, treelets or medium sized trees to 20 m

Morphology General Indumentum

Indumentum of simple hairs

Morphology Leaves

Leaves not appearing glaucous below but sometimes with domatia, base usually cuneate and symmetrical-Inflorescences usually on branches and axillary, one-flowered or seldom 2-flowered, rarely cauliflorous and then > 3-flowered; pedicels often articulated above the base

Morphology Reproductive morphology Flowers

Flowers bisexual; sepals free or rarely basally connate; petals of the outer and inner whorls equal or slightly subequal, valvate, erect or spreading at anthesis; stamens numerous, apex of anther connective flat-topped; carpels many, cylindrical or occasionally flask-shaped, ovule 1 per carpel, stigmas ±globose to ellipsoid

Morphology Reproductive morphology Fruits

Fruit apocarpous; monocarps few to many, stipitate or rarely (sub)sessile, ellipsoid(-cylindrical), apex sometimes (slightly) apiculate. Seed 1 per monocarp, (sub)globose, ellipsoid, cylindrical or rarely ±obovoid; endosperm ruminations spiniform(-flattened peg).

Ecology

Collected from primary lowland habitats including rain forest from sea level to 800 m elevation.

Recognition

Huberantha can be recognised by symmetrical leaf base and the lower surface of the leaf not being pale or glaucous, the inner petals not clawed or forming a cap or pressed tightly together over the sexual structures, the valvate petals, and the single ovule per carpel and a single seed in each monocarp. It differs from Polyalthia sensu stricto by the cuneate and symmetric leaf base, domatia sometimes present on the lower leaf surface, the single ovule in each carpel, in addition seed and pollen characters are useful to define the genera (see Chaowasku et al. 2012).