Common name: hong hua jin si tao (China), mizu-otogiri (Japan)
Triadenum japonicum (Blume) Makino APNI*
Synonyms: Elodes japonica Blume APNI*
Hypericum fauriei R.Keller APNI*
Hypericum virginicum var. japonicum (Blume) Matsum. APNI*
Hypericum virginicum var. asiaticum (Maxim.) Yatabe APNI*
Hypericum asiaticum (Maxim.) Nakai APNI*
Triadenum asiaticum (Maxim.) Kom. APNI*
Elodes virginica var. asiatica Maxim. APNI*
Elodes virginica var. japonica (Blume) Makino APNI*
Description: Perennial herb to 70 (-90) cm high, erect, with few or no branches, and with creeping and rooting base.
Leaves sessile, oblong-lanceolate to ovate-oblong, gland-dotted, 2–8 cm long, 1–1.7 cm wide, margin revolute, apex obtuse to emarginate, base shallowly cordate-amplexicaul.
Inflorescence of 1–3 flowers, occasionally with 1–3 lateral branches; flowers c. 10 mm diam.; sepals erect, obtuse, 3–4 mm long, sparsely gland-dotted; petals fleshy pink, 6–7 mm long sparsely gland-dotted near apex; stamen fascicles c. 4 mm long; filaments to half-united.
Capsule narrow-elliptic to narrow-obconical, 7–10 mm long, 5–6 mm diam., acute; seeds dark brown, c. 1 mm long.
Distribution and occurrence: only known from a swamp at Dubbo Gully near Mangrove Mountain on the Central Coast, where there are hundreds of plants over about 50 m x 5 m. This is the only location where this species is known to have naturalised (N. Robson, pers. comm.). Native of Japan, Korea, China and eastern Russia.
In its native range it is recorded from wet meadows and hillsides, marshes and lowland (Robson in Iwatsuki et al. 2006).
NSW subdivisions: *CC
Spreads by seed and locally by rhizomes. Sometimes placed in Clusiaceae.
Text by K.L. Wilson (March-April 2011), based on N. Robson (in Iwatsuki, Boufford & Ohba (2006), Flora of Japan Vol. 2a)
Taxon concept: Australian Plant Census (accessed April 2017)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.