The New Zealand Plant Conservation Network

Species

Pimelea acra

Etymology

Pimelea: from the Greek pimele, referring to the seeds
acra: after Lyall

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 - Naturally Uncommon
2004 - Range Restricted

Qualifiers

2012 - RR
2009 - RR

Authority

Pimelea acra C.J.Burrows et de Lange

Family

Thymelaeaceae

Brief Description

Low growing shrub bearing pairs of narrow pointed blue-green leaves with a few hairs on the underside and along margin (lens needed) inhabiting volcanic outcrops near Whangarei and on Little Barrier Island. Twigs hairy. Leaves slightly ridged on the underside, 5-7mm long. Flowers white, body hairy, in clusters. Fruit red.

Flora Category

Vascular - Native

Structural Class

Dicotyledonous Trees & Shrubs

Synonyms

None (first described 2009).

Distribution

Endemic. New Zealand: North Island (Whangarei Heads (Mt Aubrey, Manaia and Bream Head), Hauturu (Little Barrier Island)

Habitat

On exposed lava and eroding conglomerate ledges of forested old andesitic or basaltic volcanoes; sometimes on boulder heaps below cliffs.

Features

A medium-sized, erect to suberect, much-branched, compact or spreading shrub, up to 450 mm tall. Young branchlets usually densely clad in fine, appressed hair; internode length 2 mm or less; older stems glabrate to glabrous, greyish-brown to dark grey. Node buttresses short (0.3 mm) lunate, glabrous, dark brown, hidden by hair on young stems, moderately prominent on leafless stems. Leaves decussate, on short (0.3–1.0 mm), often red petioles, ascendant, becoming patent, not persistent; lamina 5.0–7.0 × 2.0–2.5 mm, medium green, ovate to elliptic, usually slightly keeled, uniform in size, acute, base cuneate; glabrous above with sparse or sometimes moderately dense hair below and then mainly on midvein, margins, and tip. Midvein prominent below, lateral veins not evident. Stomata usually only on upperside of leaf; some individuals have a few stomata on the lower leaf surface. Inflorescences terminal on branchlets, 4–8-flowered. Involucral bracts 4, similar in size to or wider than adjacent leaves (6–10 × 3–4 mm). Receptacle with short, dense hair. Plants gynodioecious. Flowers white, on short pedicels (0.5 mm), often circumscissile, hairy on outside, inside hairless or sometimes with a few hairs on calyx lobes or in tube. Female tube 3.5 mm long, ovary portion 2.5 mm, calyx lobes 2.2 × 1.7 mm ascendant or opening in salverform fashion; Hermaphrodite tube 5 mm long, ovary portion 2.3 mm, calyx lobes 3 × 2 mm. Anther filaments inserted at mouth of tube; anther dehiscence semi-latrorse. Ovary with cluster of short hair at summit. Fruits broad-ovoid, fleshy, red, 5 × 4 mm. Seeds ovoid 3.6 × 2.2 mm.

Similar Taxa

Distinguished from other Pimelea by the erect to suberect growth habit and medium green, rather uniformly sized, keeled leaves with appressed, relatively short hair along the lower leaf margins, midrib, and at the tip. Pimelea acra is perhaps most similar to Pimelea eremitica which is so far known only from Maunganui Bluff on the west coast of Northland. Pimelea eremitica lacks leaf hair and has white to pink fruits. Pimelea tomentosa differs from P. acra by its longer, thinner, flat, varied-sized leaves with the lower leaf surface vein patterning obvious and by the longer fine hairs, usually spread over the lower leaf surface.

Flowering

July - October

Flower Colours

White

Fruiting

September - December

Propagation Technique

Not known from cultivation. Probably easily grown from cuttings.

Threats

Pimelea acra has been listed as Pimelea (b) (AK 165780; Mt Manaia) in de Lange et al. (2004) and de Lange et al. (2009) where it was awarded the status of Naturally Uncommon, qualified RR (Range-Restricted). Currently it is believe secure at its stronghold on Mt Manaia and Bream Head. It is also locally common on Mt Aubrey in one small area. As an unpalatable cliff plant Pimelea acra is not directly threatened by browsing animals. It is possible that weeds may be an issue for this species at some sites. Its status on Hauturu (Little Barrier Island) needs further investigation as it is only known there from one 1997 gathering made from Herekohu (The Thumb).

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 6 Jan 2019