Pternandra azurea (Blume) Burk., Kew Bull. (1935)
Latin for 'bluish'.

Synonyms
Kibessia acuminatissima Merr., Kibessia azurea (Blume) DC., Kibessia azurea var. subalata (Blume) Miq., Kibessia azurea var. typica Hochr., Kibessia cordata Korth., Kibessia simplex Korth., Kibessia simplex var. oblonga Blume, Kibessia subalata Blume, Kibessia tetraptera Miq., Melastoma azureum Blume, Pternandra acuminatissima (Merr.) Nayar, Pternandra azurea var. subalata (Blume) Nayar, Pternandra borneaensis Nayar, Pternandra cordata (Korth.) Baill., Pternandra simplex (Korth.) Baill.

Description
Sub-canopy tree up to 26 m tall and 29 cm dbh. Stipules absent. Leaves opposite, simple, tripli-veined, tertiary venation faint, glabrous. Flowers ca. 15 mm diameter, blue, placed in axillary bundles or solitary, calyx with many small flower-like appendages. Fruits ca. 10 mm diameter, blue-purple, berries with flower-like appendages.

Ecology
In undisturbed mixed dipterocarp, keranga, swamp and sub-montane forests up to 1200 m altitude. Usually on alluvial sites, but also common on ridges. On clay to sandy soils. In secondary forests usually present as a pre-disturbance remnant tree.

Uses
Locally used in house building.

Distribution
Sumatra, Java, Borneo (Sarawak, Sabah, Central-, South- and East-Kalimantan).

Local names in Borneo
Pah, Polok, Puloh, Siren-siren, Siri-siri.