Common Name:

General Information

Ohwia caudata is a much-branched, erect, deciduous plant with ascending to spreading, more or less woody stems that persist. It can grow from 100 - 200cm tall[, ].
The plant is harvested from the wild for local use as a medicine and a pesticide.

Known Hazards

None known

Botanical References

,

Range

E. Asia - southern China, southern Japan, southern Korea, India, Sri Lanka, Bhutan, Myanmar, Laos, Vietnam, Malaysia, Indonesia.

Habitat

Woods in C. and S. Japan[]. Mountain slopes, roadsides, grasslands, streamsides and forest margins; at elevations from 100 - 1,000 metres in southern China[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	1.50 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Ohwia caudata is native from the warm temperate zones of China, Japan and Korea into the tropical climate of Indonesia.
Requires a well-drained soil and a sunny sheltered position[]. Tolerates soils of low fertility.
Because of the abundant small uncinate hairs on most species, the seedpods cling most tenaciously to clothing, to any part of the human body, and also to the feathers and hair of various animals, thus ensuring a wide dispersal of the plants[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

None known

Medicinal

Ohwia caudata is a traditional Chinese medicine that has long been used to treat a range of conditions. Modern pharmacological studies have shown that the plant contains a large number of medicinally active compounds including flavonoids, alkaloids, and triterpenoids[, ].
Several of these compounds have been shown to have a positive effect in the treatment of Alzheimer's disease and other types of dementia, these compounds have also been shown to work together synergisticly, giving then better oral bioavailability and blood-brain barrier permeability, making them more effective in the treatment of Alzheimer's Disease[].
The compounds have also shown activity against MRSA (methicillin-resistant Staphylococcus aureus) and inhibitory activity against the filmforming growth of Zygosaccharomyces rouxii F51[].
Flavonoids derived from the plant have shown inhibitory activity against type A influenza virus infection. In particular, the flavonoids 20-hydroxyl yokovanol and yokovanol have ben shown to inhibit viral protein activity. These compounds may be useful as a therapeutic agent or prophylactic agents to limit viral infection[].

The stems and roots are analgesic, antifungal, antiinflammatory, antioxidant, antipyretic, antiseptic, depurative and diuretic[, , ]. They are used traditionally in the treatment of various conditions including colds, fevers, rheumatic backache, gastroenteritis, diarrhoea, dysentery, icterohepatitis, abscesses, snake bites, mastitis, boils and carbuncles[, , ].

Other Uses

The roots and leaves are used as a pesticide[].
In a trial, a methane extract of the leaves at a concentration of 10,000ppm in distilled water reduced the egg hatching of root nematodes by 94% after 21 days compared with a control[].

Propagation

Seed - best sown as soon as it is ripe in a greenhouse. Scarify and pre-soak stored seed for 5 hours in warm water then sow early spring in a greenhouse. The seed usually germinates within 1 - 4 months at 25°c. Prick out the seedlings into individual pots once they are large enough to handle and grow them on in the greenhouse for their first winter. Plant them out in late spring or early summer and consider giving them some protection from frost in their first winter outdoors.
Cuttings of half-ripe wood with a heel, mid summer in a frame.
Division as the plant comes into growth in the spring. Larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.
Root cuttings in winter.