It is in fact native to western parts of Honshu and throughout Shikoku and Kyushu, growing in mountain forests and woods from 100 to 900m.

[3] Growing to 19 m (62 ft) or more, it is a deciduous anticlockwise twining woody climber with hairy leaves to 35 cm (14 in) long, each leaf comprising up to 13 leaflets.

The scented flowers, borne in late spring and early summer, are pale violet or white with a yellow blotch at the base.

It is hardy down to −20 °C (−4 °F) but needs a sheltered position in sun or partial shade, and reliably moist soil.

The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-[4]