Pimelea prostrata subsp. vulcanica
Common names
pinātoro
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Low growing shrub with sparsely hairy short twigs bearing pairs of narrow blue-green leaves that join the stem at a small ridge, hairy white flowers and white fruit inhabiting the central North Island. Leaves 4-6mm long by 1.2-2mm wide, with a ridge underneath, often red edged.
Flower colours
White
Detailed description
A small to moderately large, much-branched shrub with prostrate habit. Main stems to 600 mm long, grey-brown, relatively thin and flexible, except near the base. Branching is mainly lateral, with long, thin, flexible branchlets; secondary branchlets on these are short. Young branchlets are only sparsely hairy. Internodes 0.5–4.0 mm long. Older stems glabrous, grey-brown. Node buttresses brown, elongate, usually the whole length of the internode, with a strip of fine, short hairs between them, not very prominent on leafless stems. Leaves ascendant and imbricate; patent on laxer branchlets, on very short (0.1–0.3 mm) red petioles. Lamina narrow elliptic, 4–6 × 1.2–2 mm, glabrous, usually glaucous, medium green or sometimes yellowish-green, often red-margined, slightly keeled, acute. Mid-vein evident abaxially, sometimes reddish. Leaves on the very short lateral branchlets are relatively small. Inflorescences terminal on branchlets, 2–7-flowered. Involucral bracts 4, similar in size to adjacent leaves. Flowers white, moderately hairy outside; inside hairless or sparsely hairy in upper tube and ovary portion. Female tube 2.8 mm long, ovary portion 2.2 mm, calyx lobes 1.7 × 1.1 mm; hermaphrodite tube 4 mm long, ovary portion 1.5 mm, calyx lobes 2 × 1.4 mm. Ovary with sparse hairs at summit and about one-quarter of the way down. Fruits ovoid, fleshy, white, opaque, 4 × 2.5 mm. Seeds narrow-ovoid, 3 × 1.3 mm, thin crest.
Similar taxa
Plants of the Pimelea prostrata complex are distinguished by the prostrate to decumbent growth habit; by the glabrous to sparse or moderate hair covering on young stem internodes and by the thin and pliable, completely glabrous leaves with stomata clearly visible on both leaf surfaces. Pimelea prostrata subsp. vulcanica is distinguished from subsp. prostrata, subsp. seismica, subsp. thermalis and subsp. ventosa by the node buttresses elongate to covering the entire internode length; by the short, inconspicuous, secondary lateral branches and by the true leaves which are slightly keeled, up to 6 .0 × 1.2–2 mm and which have acute apices
Distribution
Endemic. North Island: South Auckland and Taupo district hills (abundant on the summit of Mt Tarawera, slopes of the central North Island volcanoes, and on plains of the Volcanic Plateau, and south of Murupara); scattered on Huiarau, Kaimanawa, and north-west Ruahine Ranges.
Habitat
Short grassland, shrubland with open grassy areas and sometimes on margins of fine volcanic ejecta patches (scoria, lapillii) and alluvium, colluvium derived from such debris; also on soils derived from tephra, on bared areas in grassland and open scrubland.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened
Threats
Burrows (2009) describes this subspecies as plentiful though he discusses threats which include heather (Calluna vulgaris) lodgepole pine (Pinus contorta) and sucession to taller vegetation. It probably warrrants a precautionary listing of Data Deficient.
Detailed taxonomy
Family
Thymelaeaceae
Synonyms
Pimelea heterophylla Colenso
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
September - May
Fruiting
October - July
Propagation technique
Easily grown from semi-hardwood cuttings and rooted pieces. Seed is difficult to germinate. Best grown in a well drained soil in full sun. An excellent plant for the rockery
Other information
Etymology
pimelea: Pimeleoides means “resembling Pimelea’’, a genus in the family Thymelaeaceae (Greek, -oides = resembling, like).
prostrata: Prostrate
vulcanica: Of volcanoes
Chromosome number
2n = 36
Previous conservation statuses
2017 | Not Threatened
2012 | Data Deficient
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Burrows, C.J. 2009: Genus Pimelea (Thymelaeaceae) in New Zealand 2. The endemic Pimelea prostrata and Pimelea urvilliana species complexes. New Zealand Journal of Botany 47: 163–229.
Attribution
Description from Burrows (2009).