Mitracarpus hirtus

white eye


Mitracarpus hirtus

(L.) DC. 1830

pronounced: my-truh-KAR-puss HER-tuss

(Rubiaceae — the gardenia family)


common name: white eye

Mitracarpus is from the Greek μιτρα (mitra), a head-band, chaplet, girdle, and καρπος (karpos), fruit; hirtus is Latin, rough, hairy.

This is a generally erect pubescent annual plant that can be simple or sometimes much branched. The stems are relatively stout, and can be 30 – 60 cm tall. It is native to Argentina, Paraguay, Uruguay, north to the Caribbean and through central America to Mexico. It is usually a weed of waste or cultivated ground, but is also found sometimes in pastures, on open banks, or in thickets. It is most often found at lower elevations, especially on coastal plains, but in Guatemala has been found at 1900 m. It has become naturalized as a weed in much of the tropics. In Australia it is found in Western Australia, the Northern Territory, Cape York Peninsula and in eastern Queensland as far south as Brisbane. The specimens photographed were growing behind the museum in Picnic Bay.

The leaves are between 2 and 4 cm long by 1.5 to 2 cm wide, elliptic to elliptic-lanceolate in shape, the base obtuse, the apex acute, membranous, sessile, the stipules 1 – 3 mm long. The adaxial surface is scabrid to glabrous, the abaxial glabrous.

The flowers are white, verticillate in dense axillary fascicles, and 4-merous. The bracteoles are filiform. The calyx tube is small, unequally 4-lobed, the larger two lobes about 1 mm long. The corolla is about 1.5 mm long, funnel-shaped, with 4 lobes. There are 4 stamens, attached at the throat, the anthers exserted. The ovary is 2-locular, with one ovule per locule.

Subglobose capsules are produced, only about 1 mm long, ovoid, with circumsissile dehiscence, producing 2 minute pale yellowish-brown seeds. The persistent sepals are more than 3 times as long as the fruit.

The plant is sometimes gathered in the wild for local medicinal use. The dried leaves are reputed to heal old ulcers rapidly, and the plant is used as an antidote for arrow poison.


Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.


Photographed in Picnic Bay 2018
Page last updated 7th February 2019