Hydnophytum formicarum Jack

Last updated: 22 June 2015

Scientific Name

Hydnophytum formicarum Jack


Hydnophytum blumei Becc., Hydnophytum borneense Becc., Hydnophytum montanum Blume., Lasiostoma  formicarum (Jack) Spreng. [1]

Vernacular Name

Malaysia Dedalu api laut, kepala berok, hempedal itek (Peninsular) [2]
English Smooth ant plant [3]
Indonesia Urek-urek polo (Javanese) [2]
Thailand Hua roi ruu (Central); krachao pheemot (Surat Thani); pum pao (Trat) [2]
Philippines Banghai (Bisaya) [2][3]
Vietnam Ki[ees]n k[yf] nam, [oor] ki[ees]n [2]

Geographical Distributions

Hydrophytum 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). [2]

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. [2]

Botanical Description

H. formicarum is a member of the family Rubiacea. 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. [2]

The 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. [2]

The 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. [2]

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. [2]


No documentation.

Chemical Constituent

No documentation.

Plant Part Used

No documentation.

Traditional Use

No documentation.

Preclinical Data

No documentation.

Clinical Data

No documentation.


No documentation.

Poisonous Management

No documentation.

Line drawing



Figure 1: The line drawing of H. formicarum [2]


  1. The Plant List. Ver 1.1. Hydnophytum formicarum Jack [homepage on the Internet]. c2013 [updated 2012 Mac 23; cited 2015 June 22]. Available from: http://www.theplantlist.org/tpl1.1/record/kew-100941
  2. Hydnophytum formicarum Jack. In: Lemmens RHMJ, Bunyapraphatsara N, editors. Plant Resources of South-East Asia no 12 (3): Medicinal and poisonous plants 3. Leiden, Netherlands: Backhuys Publisher; 2003.
  3. Quattrocchi U. CRC World Dictionary of Plant Names: Common names, scientific names, eponyms, synonyms, and etymology. Volume III E-L. Boca Raton, Florida: CRC Press; 2012. p. 514.