Matted St. John's Wort

Hypericum japonicum

Physical Characteristics

Hypericum japonicum is a ANNUAL/PERENNIAL growing to 0.5 m (1ft 8in). It is in flower from July to August, and the seeds ripen from August to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Distribution

E. Asia - China, Japan to Australia and New Zealand.

Habitats

Bog Garden;

Edible Uses

None known

Medicinal Uses

Antiphlogistic Depurative Dysentery Febrifuge Vulnerary The plant is alterative, antiphlogistic, astringent, depurative, febrifuge and vulnerary[147, 218, 240]. It is decocted with water for use[218]. It is used in the treatment of asthma and dysentery, acute hepatitis, pain in the liver region, appendicitis, boils and abscesses and has also been used as a styptic[147, 240, 272]. The plant has also shown antitumour activity[218].

Known Hazards

The plant is suspected of causing photo-sensitization[240]. Feeding trials to livestock in New Zealand have shown that it is non-toxic[240].