Parsonsia heterophylla A. Cunn. Apocynaceae

Kaihua, Kaiwhiria

Parsonsia is a genus of twining shrubs belonging to the Dogbane Family (APOCYNACEAE) It was named after James Parsons, (1705–1770), a London doctor, author of works on pharmacology and on seeds.

There are two principal species found in New Zealand, P.heterophylla and P. capsularis, though these will often hybridise. "Heterophylla" means "with variable leaves";"capsularis" refers to the seedpod, (see picture) though these are pretty much identical in the two species listed here.

P capsularis has leaves that are on the whole slightly longer and narrower than P.heterophylla, and the flower of P.capsularis is slightly smaller, with the anthers protruding beyond the corolla. (see illustration.)

P. heterophylla is the species seen in Woodhill forest. The Maori name is kaihua, though the name kaiwhiria (P.capsularis) is sometimes used indiscriminately for both. P. capsularis is also known as aka kiore.

Given that I have been wandering with some knowledge around areas of native bush for over fifty years, and have never before consciously met this climber in my travels I am amazed at how commonplace it is throughout both bush and pine areas in Woodhill.

It varies enormously in leaf form from juvenile to adult. Juvenile leaves are narrow, adult leaves are round. They occur in pairs, as opposed to clematis which typically has its leaves in threes.

Here is a juvenile form:

12 September 2005 Woodhill, Forest Reserve, Woodhill

Here is a vine in flower

27 October 2005 Woodhill Forest Reserve, Woodhill

The flowers are said to be fragrant, but I did not notice any fragrance to speak of. The leaves of P. heterophylla are typically rounder than those of P. capsularis, but the flowers provide the key to distinguishing the species. In P. capsularis the anthers extend beyond the corolla; in P. heterophylla the anthers remain inside the corolla:

Acknowledgements to Trees and Shrubs of New Zealand, A.L. Poole and N.M. Adams

Here is a seedpod

11 August 2005 Woodhill Forest Reserve, Woodhill

Kaihua grows readily from seed at Woodhill, and it is common to find large numbers of juveniles, in the bush reserve and under the pines. It typically ranges across the ground until it finds a host to climb, then reaches out

12 September 2005 Woodhill Forest Reserve, Woodhill

twining around itself for extra strength until it finds another anchor.

24 July 2005 Woodhill Forest Reserve, Woodhill

New Zealand Flora references

Family: Apocynaceae

Genus: Parsonsia

Species: Parsonsia heterophylla