Vitex trifolia, commonly known as the simpleleaf chastetree or blue Vitex, is a species of plant in the mint family Lamiaceae. It is a shrub or small tree native to coastal areas of the Indo-Pacific region.
Description
Vitex trifolia is a large coastal shrub or small tree, up to 8 m (26 ft) in height and a trunk up to 20 cm (7.9 in) diameter. The leaves are oppositely arranged along the stems and are usually compound, composed of three or five leaflets. The central leaflets may grow up to 12 cm (4.7 in) long and 4 cm (1.6 in) wide, and the lateral leaflets may be 5 cm (2.0 in) long and 2 cm (0.79 in) wide. The upper surfaces of the leaves are green and the lower surfaces are grayish green.
The flowers are born in panicles or clusters up to 25 cm (10 in) in length. Individual flowers have mauve or purple, five-lobed corolla tubes that are about 5 mm (0.20 in) long and 3 mm (0.12 in) wide; they are finely hairy outside and have a dense patch of longer hairs in the mouth of the tube. The stamens are 3–6 mm (0.12–0.24 in) long, and the ovary is globular and about 1.5 mm (0.06 in) diameter. The fleshy fruits are up to 6 mm (0.24 in) in diameter and contain four small seeds.
Taxonomy
Two varieties are recognised as of April 2026, Vitex trifolia var. taihangensis and the autonym Vitex trifolia var. trifolia.
Distribution and habitat
Vitex trifolia naturally occurs close to coasts in beach forest and the landward side of mangrove swamps, usually below 150 m (490 ft) altitude.
It is native to the following regions as defined in the World Geographical Scheme for Recording Plant Distributions:
Africa: Kenya, Tanzania, Somalia, Mozambique, KwaZulu-Natal, Comoros, Madagascar, Mauritius.
Asia-Temperate: Afghanistan, Iran, China North-Central, China South-Central, China Southeast, Hainan, Nansei-shoto, Taiwan.
Asia-Tropical: Assam, Bangladesh, India,...
