Alyxia R.Br.

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

Distribution

A genus of 106 species with a distribution from India throughout South-East Asia to Australia and into the Pacific as far west as Hawaii; 30 species in New Guinea (27 endemic), four in the Solomon Islands (one endemic).

Morphology General Habit

Climbers and shrubs or rarely small trees to 5 m

Morphology Branches

Branchlets frequently angled

Morphology Leaves

Leaves in whorls of 3–7, rarely opposite, usually coriaceous, equal in size within a whorl but may differ noticeably between whorls, margins frequently revolute, numerous closely parallel lateral veins from the midrib, intra-marginal vein often present

Morphology Reproductive morphology Inflorescences

Inflorescences terminal or axillary, solitary, compound cymes or paniculate

Morphology Reproductive morphology Flowers

Flowers 5-merous (in New Guinea); calyx lobes ovate to linear; corolla tube often inflated around stamens, corolla twisted to the left, lobes erect or spreading; stamens included, anthers ovate; disk absent; ovary superior, apocarpous, 2-carpellate, united by a common style; style head without a basal collar

Morphology Reproductive morphology Fruits

Fruit of globose or ellipsoid drupes, usually only 1 carpel developing, frequently moniliform with up to 6 articles in a row, each article 1-seeded.

Ecology

The genus is found in primary forests, including lowland rain forest, but especially in montane forests, and also in regrowth and scrubby areas; from c. 10–3600 m.

Recognition

Alyxia can be recognised by their whorled leaves (usually relatively small, no more than about 10 cm long), which vary in size between whorls and the leathery, frequently moniliform fruit that are pale yellow ripening to a purple-black. Most species are climbers/lianas, epiphytes or small shrubs, but some species, e.g. A. floribunda Markgr., have been described as small trees in the collecting notes.