Perrottetia Kunth

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

Distribution

A small genus of 15 species with a single species in Malesia divided into three subspecies: Perrottetia alpestris (Blume) Loes. subsp. moluccana (Blume) Ding Hou is found from the Moluccas, through New Guinea into the Solomon Islands and northern Australia.

Morphology General Habit

Shrubs or small trees

Morphology Branches

Branchlets smooth, usually zigzag

Morphology Leaves Stipules

Stipules small, caducous

Morphology Leaves

Leaves alternate, sometimes with domatia in the axils of midrib and nerves, margins entire (New Guinea) to regularly serrulate

Morphology Reproductive morphology Inflorescences

Inflorescences cymose, axillary in small divaricate thyrses generally shorter than the leaves

Morphology Reproductive morphology Flowers

Flowers bisexual, rarely unisexual, 5-merous (in New Guinea); calyx lobes short, triangular, usually valvate or with slightly imbricate margins; petals similar to the calyx lobes in shape and size (or somewhat larger), more or less distinctly keeled, valvate or slightly overlapping; disk present; stamens 5, very rarely 6–8, inserted on the margin of the disk, free, alternating with the petals, anthers lengthwise dehiscent, ±introrse; ovary semi-immersed in the disk, mostly 2-celled, or seemingly 4-celled at the base, ovules 2 per locule

Morphology Reproductive morphology Fruits

Fruit a berry, globose or subglobose, reddish-black when mature

Morphology Reproductive morphology Seeds

Seeds 2–4, erect, subglobose, thin arillate.

Ecology

Found from primary and secondary habitats, usually in montane zones up to 2700 m, but also sometimes in the lowlands.

Recognition

The genus can be recognised by the alternate leaves with entire or seemingly entire margins (and then with minute serrulations), the axillary many-flowered inflorescences, the small inconspicuous flowers with similar sized triangular sepals and petals that are usually a pale green to cream colour, and a globose fruit with the calyx (and sometimes the petals) persistent at the base.