Stellenbosch University Botanical Garden, South Africa

Common name: Johanneskruid, gammock, goatsbeard, herb-john, klamath weed, penny-john, rosin rose, St. John's-wort, Tipton's weed, touch-and-heal

Family: Hypericaceae ((see Clusiaceae))

Synonym: Hypericum perforatum

Distribution: Asia, Europe and North Africa

Habitat: Temperate regions

IUCN Red list: Not evaluated

Black list: Listed NEMBA Category 2 Invasive - May only be grown with a permit.

Life form: Shrub / sub-shrub

Comments: Effective against depression in humans. In pastures, St John's wort acts as both a toxic and invasive weed and, in large doses , is poisonous to grazing livestock causing photosensitisation (cattle, sheep, goats, horses). It invades lowlands and moutain fynbos, displacing native vegetation. Biological control through leaf feeding by the defoliating beetle (Chrysolina quadrigemina) and the stem-boring fly (Zeuxidiplosis giardi) effectively prevented H. perfoliatum from becoming a problem as it did in California and Australia.