Botanical name:

Aciphylla dieffenbachii

Common name(s):

Dieffenbach’s speargrass, soft speargrass, coxella

About:

This threatened species is native to the Chatham Islands, where its rarity is largely due to the impact of grazing animals. Its foliage is softer compared to most other Aciphylla species and has a greyish-green hue. The flowering stems grow between 60cm and 1m tall, producing clusters of bright yellow flowers in the summer.

Natural habitat:

Strictly coastal. Former habitat preferences unclear. Now only known from the Chatham (Rekohu) Island from steep, usually south facing, cliffs, rock scarps, ledges and colluvial slopes. It is usually found on basalt rather than schist rock substrates. On the outer islands, particularly those free of browsing animals it occupies similar habitats but can also be found in Poa chathamica Petrie swards, and amongst petrel burrowed ground.

Growing environment:

Frost, Sun, Drought, Coastal, Salt & Free draining tolerant.

Endemic distribution:

Endemic to the Chatham Islands where it is known from Chatham, Pitt, Mangere, Little Mangere, South East (Rangatira) islands and some of the Murumuru stacks and islets. It has also been deliberately introduced to Native Island and Ernest Islands off Stewart Island.

Height: 1m

Flowering:

November - February with a yellow coloured flower/s

Fruiting:

January – June

Uses:

Bird food / Attractant, Bee food & Riparian plantings

How to grow:

Propagation is usually by seed, although cuttings can be taken from some smaller species. Seed has short-term viability so will not store well. An attractive species ideal for a coastal situation. In good conditions spontaneous seedlings are often seen, and on occasion it can become invasive. It does best in full sun, with a moderately fertile to fertile, free draining soil. Does well in damp sand, frequently manured with sea weed. Plants should never be allowed to dry out, and even when well established are inclined to sudden collapse. This species often dies after a heavy flowering. Like most Chatham Island endemic plants this species dislikes humidity.

** Seed germinates without pre treatment. Sow seed direct & keep moist until germination is complete.