The New Zealand Plant Conservation Network

Species

Pimelea aridula subsp. oliga

Etymology

Pimelea: from the Greek pimele, referring to the seeds

Common Name(s)

Pimelea

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 Critical

Qualifiers

2012 - DP, RR, Sp
2009 - DP, RR

Authority

Pimelea aridula subsp. oliga C.J.Burrows

Family

Thymelaeaceae

Brief Description

Bushy small shrub with pairs of greyish hairy narrow pointed leaves inhabiting very dry rocky sites in Marlborough. Twigs hairy, flexible. Leaves 6-15mm long by 2-3mm wide, widest at base, pointed, hairy on both surfaces. Flowers white, in clusters. Fruit dry, enclosing black seed.

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Trees & Shrubs

Distribution

Endemic. South Island: Eastern Marlborough, relatively close to the coast in the Flaxbourne River and Wharekiri Stream catchments. Further inland in the Awatere Valley, Chalk Range and middle Clarence Valley (West of the Seaward Kaikoura Range)

Habitat

Lowland to montane. On limestone outcrops and screes (occasionally on sandstone)

Features

A medium-sized, slender upright shrub, up to 0.7 m. Long-stemmed plants may be fastigiate; short-stemmed plants often have more divergent branches. Branching mainly sympodial. Main stems flexible. Young branchlets brown, moderately to densely covered with long hair; internodes 0.5-2.0 mm; old stems at the base may be stout (= 10 mm diameter), grey-brown, glabrous. Node buttresses lunate, brown, hairy, often masked by hairs on young stems, moderately conspicuous on leafless stems. Leaves usually decussate, on short, red petioles (0.5 mm), rarely alternate on some young branchlets, ascending, loosely imbricate. Lamina 6-15 × 2-3 mm, medium green, slightly adaxially concave, narrow-ovate, acute, base cuneate, both surfaces sparsely to moderately densely covered by appressed white sericeous to villous hairs, comose at tip. Stomata on both leaf surfaces. Inflorescences terminal, 5-10-flowered, sometimes in small clusters. Involucral bracts similar in size to adjacent leaves or slightly wider (8.0-10 × 3.2 mm), partly hiding the flowers. Receptacle densely hairy. Plants gynodioecious. Flowers white, on short pedicels (0.5 mm), densely hairy outside, internally glabrous. Female tube 3.0 mm long, ovary portion 2 mm, calyx lobes 1.3 × 0.7 mm; hermaphrodite tube 6.0 mm long, ovary portion 2.5 mm, calyx lobes 2.0 × 1.3 mm. Anther dehiscence introrse. Ovary hairy from summit to two thirds of the way down. Fruits ovoid, dry, brown, 4.0 × 2.3 mm. Seeds ovoid 3.0-4.0 × 1.9-2.1 mm.

Similar Taxa

Pimelea aridula subsp. oliga is most likely to be confused with P. concinna, a species with which it is sometimes sympatric. Both Pimelea form relatively tall shrubs with mostly upright growth habits. From Pimelea concinna, P. aridula subsp. oliga can be distinguished by the leaves which are 8-12 mm rather than 5-8 mm long. Pimelea aridula subsp. oliga differs from subsp. aridula by its allopatric distibution (being geographically confined to Marlborough) and vegetatively by shorter growth habit with notably more slender, flexible stems, and by the narrow-elliptic to narrow-ovate leaves whose surfaces are usually sparsely to moderately invested by long sericeous to villous white hairs.

Flowering

October - January

Flower Colours

White

Fruiting

December - May

Propagation Technique

Easily grown from semi-hardwood cuttings. Does best in a free draining, sunny site, planted within a rich. fertile soil. Dislikes competition from taller plants and humidity. Will not long tolerate being shaded out. An excellent pot plant or small shrub for a rockery.

Threats

Pimelea aridula subsp. oliga is listed in Appendix 2 of de Lange et al. (2011; p.90) as Pimelea aff. aridula (CHR 277514; South Marlborough). Burrows (2011) offers no data to support or refute that status, though he does indicate this subspecies is highly threatened, citing farming as a major threat through causing a of loss of habitat. Burrows (2011) also provides data to suggest that introgression with other Pimelea may be a threat. This needs to be properly studied. At this stage because Pimelea aridula subsp. olga has a valid threat status, until a further listing is undertaken there seems no reason to change this.

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 6 Jan 2019