Hypericum japonicum Thunb. ex Murray

Hypericum japonicum Thunb. ex Murray

Family

Guttiferae

Synonyms

Hypericum pusillum Choisy, Hypericum mutilum Maxim. non L., Sarothra  japonica (Thunb. ex Murray) Y. Kimura.

Vernacular Names

Papua New Guinea Ngo­tokong (Mt Hagen, Western Highlands).
Vietnam N[ojc] s[owr]i c[or] ban, di[eef]n crow] ho[af]ng.

Geographical Distributions

Hypericum japon­icum is from Japan, South Korea and south-eastern China, Nepal, India and Sri Lanka to Australia, New Zealand and Hawaii. Hypericum japon­icum occurs throughout Malesia, Indo-China and Thailand.

Description

Hypericum japon­icum is an extremely variable annual herb, reaching up to 2-50 cm tall, and with erect to decumbent or prostrate stems rooting at the base.

The leaves are usually ovate or ovate-triangular to oblong or elliptical, measuring 2-18 mm x 1-10 mm, chartaceous, sometimes glaucous at the lower side, with 1-7 basal veins which are usually without reticulate venation, with pale laminar glands and sessile.

The 1-30-flowered inflorescence is lax. The flowers are 4-8 mm in diametre. The free sepals are 3-5-veined, measuring 2-5.5 mm x 0.5-2 mm, ,and often with prominent midrib and pale laminar glands while the petals are persistent, measuring 1.7-5 mm x 0.8-1.8 mm,  pale yellow to orange and without glands. There  are 5-30 stamens in 5 irregular groups. The ovary is 1-celled, with 2-3 parietal placentas, with divergent style and with broadening to headed stigmas.

The fruit is 2-6 mm long and cylindrical to spherical. The cylindrical seeds are minute, longitudinally ribbed with striae and not keeled.

Ecology / Cultivation

Hypericum japon­icum is found in wet or marshy to dry locali­ties, but always in exposed places, from sea level up to 3400 m altitude.

Line Drawing / Photograph

Hypericum_japonicum

References

  1. Plant Resources of South-East Asia No. 12(1): Medicinal and poisonous plants 1.