Uromyrtus Burret

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

Distribution

A genus of 22 species, distributed from Borneo to New Guinea, Australia and New Caledonia; four species occur in New Guinea.

Morphology General Habit

Shrubs and small trees to 6 m tall

Morphology Leaves

Leaves opposite, coriaceous, elliptic, 1–2(–4) cm long, apex acute to acuminate, midrib may have a pale pubescence, venation obscure on upper surface, intra-marginal vein not prominent

Morphology Reproductive morphology Inflorescences

Inflorescences axillary, 1–3-flowered

Morphology Reproductive morphology Flowers

Flowers (4–)5-merous, white or pink, peduncles pendant; sepals free, erect, rounded, persistent in fruit; petals free; stamens many, free, in several rows, with prolonged connectives that extend beyond the anthers and form a conspicuous apical appendage; style slender; ovary inferior (2–)3-locular, ovules in 2 vertical rows

Morphology Reproductive morphology Fruits

Fruit a fleshy berry

Morphology Reproductive morphology Seeds

Seeds 1–many; embryo curved with small cotyledons.

Ecology

Uromyrtus is has been recorded in New Guinea from montane and subalpine habitats between 550–2500 m.

Recognition

Uromytrus can be distinguished from other small-leaved, fleshy-fruited Myrtaceae by its pendant solitary flowers and by its conspicuous staminal appendages which extend beyond the anthers. Another useful character for Uromyrtus is the pale pubescence that is usually present on the twigs and midribs (but rarely the lamina). Uromyrtus can be distinguished from Decaspermum by its 3-locular ovary (4–5-locular in Decaspermum) and pendant flowers (erect in Decaspermum). Uromyrtus can be distinguished from Xanthomyrtus by its 5-merous, pink or white flowers (4-merous and yellow in Xanthomyrtus). Uromyrtus twigs and leaves frequently have some sort of pubescence, whereas Xanthomyrtus and the montane species of Decaspermum are usually glabrous.