Hydnophytum formicarum Jack

Family

Rubiaceae

Synonyms

Hydnophytum montanum Blume

Vernacular Names

Geographical Distributions

H. formicarum is widely distributed, from the Andaman Islands, peninsular Burma (Myanmar), southern Thailand and southern Cambodia and Vietnam, through the whole of Malaysia, to the Solomon Islands and northern Australia (Cape York).

Description

This is an epiphytic subshrub that can grow up to 60 cm tall, with a few quadrangular stems (usually 2-4) which are arising from a tuber-like swollen base that up to 25 cm long. The inside is with labyrinth, covered with scales.

Leaves are arranged decussately opposite, simple and entire, elliptical to broadly lance-shaped, often broadest above the middle part, 4-15 cm x 2-7 cm. Its base is acute, obtuse to rounded apex, leathery, hairless and pinnately veined. The petiole is 0.5-4 cm long. Stipules are interpetiolar.

Flowers are together in shallow, cup-shaped cavities in strongly thickened nodes of the stem, bisexual, 4-merous and sessile. The sepal is bell-shaped-urn-shaped, hairless or sparsely papillose, limb truncate and persistent. Petal is tubular where the tube is about 3 mm long, elliptical lobes, thickened at apex and white. The stamens are inserted in the throat of the petal, alternating with bundles of hairs. The disk is ring-shaped and thick. The ovary is inferior with 2-celled, filiform style and exserted. Stigma is 2-branched, thick and papillose.

The 6-7 mm long fruit is narrowly obovoid drupe, constricted at apex, orange when ripe and with 1-2 pyrenes that are about 5 mm long. 

Ecology / Cultivation

H. formicarum is an epiphyte of trees (mostly colonising branches rather than trunks) in primary and secondary forests, most abundant in seasonal, open forest, up to 1000 m altitude. It also occurs in 'kerangas' vegetation and comparatively often in mangrove vegetation and Casuarina trees.

Line Drawing / Photograph

References

1. Plant Resources of South-East Asia No.12(3): Medicinal and poisonous plants 3.