The New Zealand Plant Conservation Network

Species

Olearia crebra

Etymology

Olearia: Derived from the latinised name (Olearius) of the 17th century German botanist Adam Oelenschlager

Common Name(s)

None known

Current Conservation Status

2012 - Threatened - Nationally Endangered

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 Endangered
2004 - Threatened - Nationally Endangered

Qualifiers

2012 - RR
2009 - CD, RR

Authority

Olearia crebra E.K.Cameron et Heenan

Family

Asteraceae

Brief Description

Small tree bearing very large leathery leaves that have a rusty brown fuzzy underside inhabiting upland Waima Forest in Northland. Leaves 80-290mm long. Flowers white with yellow centre, body 10-12mm long. Seeds small, with a hairy tip.

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Trees & Shrubs

Synonyms

None

Distribution

Endemic. North Island, Waima Forest, where it is known from the local high points of Hauturu, Te Raupua and Mt Misery.

Habitat

In cloud forest. Now primarily on cliff faces although this habitat is probably not entirely natural, the cliffs acting as a refugia from goats and other browsing animals which periodically plague this species only known habitats.

Features

Small tree 4-7 m tall, with upright to spreading growth form. Bark light grey, somewhat rough and peeling off in small plates. Petiole 10-20 x 2-2.45 mm. Leaves clustered in groups of 8-12 at branch apices, alternate, 80-290 x 45-120 mm, elliptic, obovate to oblanceolate, coriaceous, upper surface dark green, under sides covered in red brown appressed tomentum; lamina margin somewhat sinuate, apex obtuse; base cuneate to attenuate. Inflorescence a lateral panicle of 210-220 capitula. Capitulum 10-12 mm long. Pedicel 7-15 mm long, densely invested in short fulvous hairs. Involucre cylindrical, bracts (30-)40-54, spiraled in 7-9 rows, light brown, recurved at maturity; outer bracts 1.5-2.6 x 0.8-1.4 mm, narrowly triangular, outer surface sparsely to moderately hairy, margins fimbriate. Florets 18-26 per capitulum. Ray-florets 10-15, pistillate; corolla glabrous, tube 2.7 mm long, ligulate with deflexed white limb 3.5-8 x 1.2-1.6 mm, 2-3-lobed at apex. Disc florets 8-11, hermaphrodite, corolla glabrous, white, tube 3.3. mm long, lobes 5, 1.5 x 0.6 mm. Seeds (cypselae) 1.7-3 x 0.4-0.5 mm, narrow-cylindric, brown, 5-6-ribbed, glabrous to sparsely hairy; pappus 3.5-4.5 mm, cream, finely scabrid.

Similar Taxa

None. Well marked by the small tree habit, very large leaves with red-brown undersides, and large number of involucral bracts. This last character it shares with O. pachyphylla Cheeseman, which is otherwise a much smaller shrub, with smaller leaves and capitula which have 1-3 ray florets.

Flowering

November to January

Flower Colours

White,Yellow

Fruiting

January to April

Propagation Technique

Difficult except in damp cool climates. Can be grown from semi-hardwood cuttings and fresh seed. Very susceptible to phytophora and verticillium wilt, and so prone to sudden collapse in gardens located within warm or humid climates.

Threats

Severely threatened by animal browse, especially as this species is known from only four very small populations located within vulnerable ridges crests frequented by feral goats, cattle, horses and possums. Despite on going wild animal control, this species remains very vulnerable to even small numbers of these animals.

Chromosome No.

2n = 108

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 7 May 2014