The New Zealand Plant Conservation Network

Species

Pimelea mesoa subsp. mesoa

Etymology

Pimelea: from the Greek pimele, referring to the seeds

Common Name(s)

Pimelea

Current Conservation Status

2012 - Not Threatened

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 - Data Deficient

Qualifiers

2012 - DP

Authority

Pimelea mesoa subsp. mesoa C.J.Burrows

Family

Thymelaeaceae

Brief Description

Low shrub to 10cm tall bearing pairs of blueish-green pointed leaves that are hairy underneath and with hairy white flowers and orange fruit inhabiting valleys in the vicinity of Marlborough and north Canterbury. Leaves 4.5-7mm long by 1.8-2.5mm wide.

Flora Category

Vascular - Native

NVS Species Code

PIMMSM

Structural Class

Dicotyledonous Trees & Shrubs

Synonyms

None (first described in 2011)

Distribution

Endemic. New Zealand: South Island (intermontane basins and adjacent river flats of the upper Wairau, Clarence and Awatere to the Waiau-uha, Hurunui and Waimakariri

Habitat

Montane to alpine. A common species of intermontane basins and their associated river flats and alluvial terraces. Pimelea mesoa subsp. mesoa is mostly found within short tussock grassland where it commonly grows amongst Poa colensoi, Festuca novae-zelandiae, Raoulia spp. It also occasionally grows in open shrubland.

Features

A small much-branched, suberect, or decumbent, sometimes appressed, shortly branched compact shrub fomring ± circular patches up to 200 mm diameter. Branching mainly sympodial, branches radiating from a stout main stem. Branches of young stems dark brown, moderately to densely covered with long grey-white or yellowish hairs, internodes 0.5–2.5 mm long. Older stems stout (to 10 mm), black, glabrate to glabrous. Node buttresses lunate to elongate, brown, prominent on leafless stems. Leaves decussate, ascending tightly imbricate, becoming patent, on short (0.3-0.5 mm) reddish petioles. Lamina 4.5-7.0 × 1.8-2.5 mm, dull glaucous-green, elliptic, broad-elliptic or oblong, sometimes ovate, slightly adaxially concave, mid-vein obscure; tip obtuse; base cuneate; abaxial surface moderately densely covered with long, straight or curled hairs; stomata on both adaxial and abaxial leaf surfaces. Inflorescences terminal, 4-12-flowered; involucral bracts 4, wider than ordinary leaves (6-8 × 3-4 mm). Receptacles densely hairy. Plants gynodioecious. Flowers white, scented, on short (0.2 mm) pedicels, very hairy outside, inside hairless. Female tube 3-4 mm long, ovary portion 2 mm, calyx lobes 2 × 1 mm; hermaphrodite tube 5-6 mm long, ovary portion 1.5 mm, calyx lobes 3 × 1.5 mm. Anther dehiscence introrse. Ovary with sparse short hairs on apex. Fruits ovoid, fleshy, yellow to orange 4.0-5.0 × 2.0-3.2 mm. Seeds 2.5 × 1.3 mm.

Similar Taxa

Pimelea mesoa has been confused in the past with Pimelea sericeovillosa from which it differs by its larger size, upright or elongate, prostrate stems, larger, adaxially glabrous leaves and larger, more numerous flowers. From P. oreophila with which it often grows, it can be distinguished by the abaxially densely hairy leaf surface and by the obtuse leaf tips. Pimelea mesoa subsp. macra differs from subsp. mesoa by its more slender root stock, procumbent laxer growth habit, longer non-radiating stems, longer internodes (2.0-5.0 mm cf. 0.5-2.5 mm in subsp. mesoa) less tightly imbricating and lax leaf arrangement.

Flowering

September - February

Flower Colours

White

Fruiting

Unknown

Propagation Technique

Unknown. Probably easily grown from semi-hard and hardwood cuttings.

Threats

Probably not threatened. However, some populations are small and are possibly threatened by competition from hawkweeds (Pilosella spp.). However as Pimelea mesoa subsp. meosa was not assessed by Burrows (2011) using the New Zealand Threat Classification Manual (Townsend et al. 2008) it has no valid threat assessment. So at this stage it seems best to recommend an interim threat assessment of "Data Deficient".

Chromosome No.

2n = 36

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 7 Nov 2013