Pimelea orthia susbp. orthia
Common names
pimelea
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Bushy shrub to 90cm tall with many erect hairy branches bearing pairs of blue-green leaves and hairy white flowers and white fruit inhabiting the upper North Island. Leaves 5-8mm long by 2-3mm wide.
Flower colours
White
Detailed description
Fastigiate to bushy, few to much-branched shrubs, up to 900 mm tall, often shorter, with relatively few, stiffly erect or divergent to prostrate, straight main branches and thin, usually ascendant, lateral branches of varied form. On different plants these may be short and straight, long and straight, or short and repeatedly sympodially branched. Young branchlets clad in sparse to moderately dense, appressed, grey-white, short, silky hair; internodes 0.5–2.5 mm, older stems glabrous, grey or brown (bark wrinkled on dried specimens). Node buttresses brown, extending part way down or the full length of the internode, not very prominent on leafless stems. Leaves decussate, ascendant, then patent or deflexed, on short (0.5 mm) red petioles, often persistent. Lamina flat to slightly keeled, relatively thin, 5–8 × 2–3 mm (smaller on lateral branchlets), elliptic or ovate, glabrous, glaucous or pale green, acute, but tip blunt, or obtuse. Stomata abundant on adaxial and abaxial sides. Inflorescences terminal on main stems or lateral branchlets, 2–12-flowered, loose. Involucral bracts 4, similar in size to adjacent leaves or slightly wider (7 × 3 mm), partly hiding the flowers. Receptacles moderately hairy. Plants gynodioecious. Flowers white on short pedicels (0.8 mm); outside of tube and calyx lobes moderately hairy; inside hairy in upper tube and ovary portion. Female tube 2 mm long, ovary portion wrinkled, 1.7 mm long, calyx lobes 1.2 × 1.0 mm; hermaphrodite tube 3.2 mm long, ovary portion 1.5 mm, calyx lobes 2.7 × 1.4 mm. Anther dehiscence semilatrorse. Ovary summit sparsely hairy. Fruits fleshy, ovoid, white, opaque, 5 × 2.9 mm. Seeds broadovoid 2.1 × 1.4 mm. Crest thin.
Similar taxa
Pimelea orthia is part of the P. prostrata complex. Burrows (2009) allies it with P. xenica and P. actea; species from which it is distinguished by its much-branched mostly erect growth form. Within P. orthia Burrows (2009) recognises two subspecies of which subsp. protea is not accepted here because the distinctions offered are not maintained in cultivation, they are seen also in other populations of subsp. orthia, and the claims of ecological differences between both subspecies are incorrect. Further investigation into the status of subsp. protea is required.
Distribution
Endemic. North Island: North Auckland (scattered localities from Mangonui to Auckland City), South Auckland-King Country, Coromandel Peninsula, eastern Bay of Plenty (Whakatane, Kohi Point, Ohiwa Harbour); East Cape – Gisborne (near Ngatapa), Mahia.
Habitat
Coastal to lowland. In open scrubland and grassland overlying leached, infertile soils, or on dunes and rock outcrops.
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 | Threatened – Nationally Critical | Qualifiers: Sp
Threats
Probably highly threatened but until Burrows (2009) established the exact taxonomic status of this plant it has been widely confused with a range of other members of the P. prostrata complex. Recent (2000+) records have come from near Mangawhai, near Whakatane, Ohiwa Harbour and at Mahia Peninsula. Most of these sites are roadside or trackside habitats vulnerable to clearance. However, a definitive threat status cannot be given until better information is obtained, until such time this species probably warrants the current threat listing awarded it by de Lange et al. (2009) where it is listed under Appendix 2, as Data Deficient under the illegitimate name Pimelea prostrata var. erecta Cheeseman
Detailed taxonomy
Family
Thymelaeaceae
Synonyms
Pimelea laevigata var. erecta, Pimela prostrata var. erecta nom. illeg.; Pimelea orthia subsp. protea C.J.Burrows et Thorsen
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
September - May
Fruiting
November - July
Life cycle and dispersal
Fleshy drupes are dispersed by frugivory (Thorsen et al., 2009).
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).
Chromosome number
2n = 36
Previous conservation statuses
2017 | Threatened – Nationally Critical | Qualifiers: Dp, Sp
2009 | Data Deficient
2004 | Data Deficient
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.
de Lange, P.J.; Norton, D.A.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Hitchmough, R.; Townsend, A.J. 2009: Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47: 61-96.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (13 December 2009). Description adapted from Burrows (2009).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pimelea orthia susbp. orthia Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pimelea-orthia-susbp-orthia/ (Date website was queried)