The New Zealand Plant Conservation Network

Species

Aciphylla dieffenbachii

Etymology

Aciphylla: From the Latin acicula 'needle' and the Greek phyllum 'leaf', meaning needle-leaf.
dieffenbachii: Named after Dr. Ernst Dieffenbach, 19th century German naturalist

Common Name(s)

Dieffenbach’s speargrass, soft speargrass, coxella

Current Conservation Status

2012 - Threatened - Nationally Vulnerable

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Threatened - Nationally Vulnerable
2004 - Threatened - Nationally Vulnerable

Qualifiers

2012 - CD, EF, IE, RR
2009 - CD, EF, IE, RR

Authority

Aciphylla dieffenbachii Kirk

Family

Apiaceae

Flora Category

Vascular - Native

NVS Species Code

ACIDIE

Structural Class

Dicotyledonous Herbs other than Composites

Synonyms

Gingidium dieffenbachii F.Muell., Ligusticum dieffenbachii Hook.f., Angelicia dieffenbachii Benth, et Hook.f., Coxella dieffenbachii (F.Muell.) Cheeseman et Hemsl.

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.

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.

Features

Tufted, dioecious, perennial with extremely stout, napiform taproot. All parts exuding white, sticky latex when damaged. Leaves glaucous, flaccid, up to 0.7m long. Petiole broadly sheathing near lamina junction, furnished on either side by blunt lobes. Leaf lamina 150–400 × 100–300 mm. Primary pinnae 4–7 pairs, segments up to 90 × 5 mm, linear, flaccid, apices bluntly mucronate. Inflorescence up to 1.0 × 0.6m diameter, rather stout, almost woody. Umbels numerous, subpaniculate. Peduncles rigid, stout, 50–150 mm long. Primary bracts pinnatisect with broad base. Male umbels with up to 15 rays, 10 mm long, slender; female umbels similar but with 3–6 rays. Involucral bracts linear–lanceolate, acuminate. Flowers golden–yellow. Male flowers with distinct triangular acute calyx–teeth; petals 2 mm long, oblong to ovate–oblong. Female calyx–teeth narrowly triangular, subacute; petals 1.5 mm long, obovate. Fruit 15 × 10 mm, golden yellow maturing light brown-grey, dorsally flattened, splitting at maturity into 2 more or less equal mericarps, these 2–3 winged, wings up to 3 mm wide.

Similar Taxa

One of only two species of Aciphylla on the Chatham Islands. A. dieffenbachii is a strictly coastal species which differs from A. traversii (F.Muell.) Hook.f. by the flaccid, more heavily divided, glaucous, blunt-tipped leaves, shorter (up to 1 m), fewer though much stouter and denser inflorescences with golden yellow flowers, and much larger fruits. By comparison A. traversii is a species of peat bogs, lake margins and peaty ground in open forest clearings. It has much larger, less flaccid and less divided dark green, sharply-tipped leaves, more numerous, taller (up to 1.8 m) distnctly narrower, more open inflorescences with cream-coloured flowers, and smaller fruits.

Flowering

November - February

Flower Colours

Yellow

Fruiting

January - June

Propagation Technique

Easy from fresh seed. 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.

Threats

Domestic stock and feral mammals are the prime threats. Rodents probably eat seeds and seedlings; possums probably eat flowers and seedlings. The speargrass weevil (Hadramphus spinipennis) is dependent on the speargrass, but can be locally very damaging: adults eat stems, flowers and leaves; larvae eat roots as well. Thick exotic grass swards may inhibit seedling establishment.

Chromosome No.

2n = 22

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Winged schizocarps are dispersed primarily by wind (Thorsen et al., 2009).

This page last updated on 19 Dec 2014