The New Zealand Plant Conservation Network

Species

Pimelea microphylla

Etymology

Pimelea: from the Greek pimele, referring to the seeds
microphylla: small leaf

Common Name(s)

Pimelea

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - At Risk - Declining
2004 - Range Restricted

Qualifiers

2012 - RR, Sp
2009 - RR, SP

Authority

Pimelea microphylla Colenso

Family

Thymelaeaceae

Brief Description

Cushion-forming small-leaved central North Island endemic shrub bearing leaves densely crowded near the tip of twigs and numerous small hairy white flowers and whitish fruits . Leaves 2.5-3.0mm long, by 1-2mm wide, hairy on the underside or at tip when young (lens needed).

Flora Category

Vascular - Native

NVS Species Code

PIMMIC

Structural Class

Dicotyledonous Trees & Shrubs

Synonyms

Pimelea polycephala Colenso, Pimelea laevigata var. alpina Cheeseman

Distribution

Endemic. North Island: Central Volcanic Plateau from Kaingaroa - Rangitikei south across the Kaimanawa and Kaweka Ranges and west across the Rangipo Desert including Mt Tongariro, Ngauruhoe and Ruapehu.

Habitat

Bare or sparsely vegetated scoria, lapilli, tephra, pumice flats and coarser volcanic debris; sometimes in crevices on solid volcanic rock; also on bare soil and stony debris on surfaces covered by old tephra on windswept high ridges of the sandstone ranges, to 1650 m.

Features

A small, compact, prostrate to suberect, much-branched shrub forming loose cushions, to 60 mm high and 250 mm diameter, with short, notably sympodial branching. Young branchlets moderately to densely clad in short, grey hair, on strips between glabrous node buttress tissue; internode lengths 0.25–0.6 mm, rarely to 1 mm; older stems sparsely hairy to glabrous, grey-brown to blackish. Narrow node buttresses occupy the length of the internodes and are prominent on leafless stems. Leaves decussate, ascendant, imbricate, and crowded near the ends of branchlets, on very short (0.1–0.3 mm) red petioles, or sessile. Mature leaves glabrous, but almost all plants have some young leaves with a few short hairs at the distal end and young leaves of some individuals are moderately densely hairy, above. Lamina broad-elliptic or broad-ovate, 2.5–3.0 × 1.0–2.0 mm, upper surface concave to slightly keeled, leathery, medium green to yellowish-green; sometimes margins are slightly upturned and red-margined, midvein obscure; obtuse, base cuneate. Stomata on both leaf surfaces. Inflorescences terminal on branchlets, 1–4-flowered; receptacles with short, dense to sparse hair. Involucral bracts 4; 2.5–3.5 × 2–2.5 mm, broad-elliptic to broad-ovate, often with a few hairs at the distal end or sometimes densely hairy below. Plants gynodioecious. Flowers white or sometimes pale red, on very short pedicels (0.1 mm); tube and calyx lobes hairy outside; inside hairless, or with sparse hair in the style portion. Female tube 3.2 mm long, ovary portion 3 mm, calyx lobes 1.3 × 1 mm; hermaphrodite tube 3.2 mm long, ovary portion 1.8 mm, calyx lobes 1.5 × 1.5 mm. Anther filaments inserted just below mouth of tube; anther yellow. Ovary moderately hairy at summit, sparsely hairy elsewhere. Fruits oblate, fleshy, white or sometimes pink, opaque, 5.5 × 4.2 mm. The tube breaks off irregularly as the fruits ripen. Seeds pyriform, surface granulate, thin crest, 3 × 2 mm.

Similar Taxa

Pimelea microphylla is superficially similar to, and has been included in the Pimelea prostrata complex. The most recent treatments of the genus (Burrows 2009a,b) treat P. microphylla as a separate from P. prostrata but do not explain why. From the P. prostrata complex P. microphylla differs by its smaller more compact cushion-forming growth habit, erect, sympodial broanching habit with the leaves crowded toward the branchlet apices, pale yellow-cream (rarely reddish tinged flowers). The fruits of P. microphylla are often coloured pink.

Flowering

November - February

Flower Colours

Red / Pink,White

Fruiting

January - May

Propagation Technique

Can be grown from semi-hardwood cuttings. However, plants are often very slow to establish and dislike competition and excessive moisture or humidity. Probably best grown in a rock garden or alpine house

Threats

Pimelea microphylla may be threatened. There is some evidence that it is declining over parts of its range due to the spread of heather and on the Kaingaroa Plain at least, habitat modification for farming and forestry.

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 11 Nov 2014