Triphasia Lour.

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

Distribution

A genus of three species, distributed from mainland South-East Asia to New Guinea. One native species in New Guinea Triphasia brassii (C.T.White) Swingle and one widely cultivated species, T. trifolia (Burm.f.) P.Wilson.

Morphology General Habit

Shrubs, 1–3 m tall, rarely reaching 5 m. Plants more or less glabrous

Morphology General Spines

Paired axillary spines present

Morphology Leaves

Leaves alternate, sometimes distichous, simple or trifoliolate, petioles short, not articulated, 1–4 cm long (in New Guinea), chartaceous, margins entire to crenate, gland dots present

Morphology Reproductive morphology Inflorescences

Inflorescences axillary, flowers solitary or in groups of 2–3

Morphology Reproductive morphology Flowers

Flowers bisexual, 3- or 5-merous; calyx cupular, lobes free or fused, persistent in fruit; petals linear, free; stamens twice as many as petals, free, filaments slender; disk annular; ovary syncarpous, 3–5-locular, ovules 1–2 per locule, style short, stigma capitate

Morphology Reproductive morphology Fruits

Fruit an ovoid to globose fleshy berry, gland dots present on exocarp

Morphology Reproductive morphology Seeds

Seeds 1–4 per fruit, embedded in the mucilaginous pulp.

Ecology

Triphasia are understorey shrubs in rain forest in New Guinea, often near the coast, and are cultivated as an ornamental plant, often in hedges.

Recognition

The genus can be recognised by the presence of paired spines, the alternate, simple or trifoliolate leaves, the few-flowered axillary inflorescences with 3-merous or 5-merous flowers and the 3–5-locular ovary with 1–2 ovules per locule.