Meliosma Blume

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

Distribution

A genus of c. 50 species in South-East Asia to southern China, and in South and Central America; a single species in New Guinea: Meliosma pinnata (Roxb.) Maxim. which is quite variable in its morphology and several indistinct varieties have been named.

Morphology General Habit

Trees to 42 m (in New Guinea) or shrubs, sometimes scrambling

Morphology General Indumentum

Indumentum of brownish hairs

Morphology Leaves

Leaves imparipinnate, sometimes simple (not in New Guinea), leaflets entire to dentate; petiole usually thickened and woody at base

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, sometimes axillary, a pyramidal panicle, usually many-flowered and large

Morphology Reproductive morphology Flowers

Flowers hermaphroditic, zygomorphic, sessile or shortly pedicellate; sepals (4–)5, imbricate, with bracts beneath; petals 5, imbricate, unequal, 3 outer ones larger, 2 inner ones much smaller, ±adherent to base of filaments of fertile stamens, concealed under outer petals at bud stage; fertile stamens 2, opposite 2 inner petals; filaments flattened, short, incurved at apex into a cup-shaped connective; anthers 2-celled, globose or elliptic; staminodes 3, opposite outer sepals, adherent to their bases; disk cup-shaped to dentate; ovary superior, 2(or 3)-loculed, with 1 or 2 ovules per locule

Morphology Reproductive morphology Fruits

Fruit a drupe, small; mesocarp fleshy; endocarp stony or crustaceous

Morphology Reproductive morphology Seeds

Seed ±globose, usually somewhat concave ventrally, without endosperm.

Ecology

Meliosma is found in a variety of primary and secondary habitats including lowland rain forest, disturbed rain forest, Nothofagus forest, and montane forests to 3000 m.

Recognition

The genus can be recognised by the imparipinnate leaves with opposite leaflets with the petiole, and petiolules, often swollen and woody at the base, the large inflorescences with numerous small flowers, the flowers with 2 fertile stamens and three staminodes and the relatively small fruits which are drupes with a distinct ridge, or keel, running across the top and sides of the fruit, especially when dry. In addition, the genus is often covered with brown hairs and dries with a brown or ginger colour