Vigna caracallaThis is a climbing plant with fragrant, corkscrew-like flowers coloured pink, purple and cream through the warmer months and into autumn. Its previous name was Phaseolus caracalla. It is sometimes known as the snail creeper, and the flowers do look a bit like snail shells. One can only wonder at what evolutionary process led to such a floral form. It grows quickly from seed as a light, twining vine and tends to die back a bit during winter in its early years, to re-sprout in spring, but after a few years its woody form becomes more permanent and it can reach a height of up to 6 m.
Vigna caracalla growing on an arch in the garden of Margaret Chedra in SydneyIt can cover fences, arches and pergolas. It grows best in full sun, in well-drained soil enriched with organic matter. The old tangled growth can be cut back in late winter. It is related to the edible bean (in the Leguminosae family of plants), as can be seen in its palmate foliage. Propagation is by seed from the long seedpods that appear in autumn. It comes from tropical South America so is frost tender. I have yet to plant mine out but even growing in a pot it has sent out tendrils to cover the roof of our chook-pen!
In recent times this plant has been reclassified again, now being officially known as Cochliasanthus caracalla!
Best grown from seed.