About Hypericum japonicum Thunb.
Hypericum japonicum Thunb. is an unusually small species of St. John's wort, growing only 2โ5 cm (0.8โ2.0 in) tall. Its stems are green and four-angled, with internodes 2โ52 mm (0.1โ2.0 in) long that are usually longer than the leaves. The leaves are sessile, spreading, and persist on the plant. This species produces up to 30 flowers, which branch from up to three nodes. The flowers are 4โ8 mm (0.16โ0.31 in) in diameter, with bright yellow or orange petals. It has between 5 and 30 stamens, arranged either in irregular groups, or in five groups when there are few stamens. Its seeds are approximately 0.5 mm long. Hypericum japonicum primarily flowers from October to March. The seeds of this species closely resemble those of the extinct fossil species Hypericum tertiaerum. The species is distributed across the Indian subcontinent, China, Southeast Asia, and Oceania. While it was previously recorded as occurring in Hawaii, this record was later determined to be an error.
