Shawia crebra
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Small tree bearing very large leathery leaves that have a rusty brown fuzzy underside inhabiting upland Waima Forest in Northland. Leaves 80-290 mm long. Flowers white with yellow centre, body 10-12 mm long. Seeds small, with a hairy tip.
Flower colours
White, Yellow
Detailed description
Small tree 4-7 m tall, with upright to spreading growth form. Bark light grey, somewhat rough and peeling off in small plates. Petiole 10-20 x 2-2.45 mm. Leaves clustered in groups of 8-12 at branch apices, alternate, 80-290 x 45-120 mm, elliptic, obovate to oblanceolate, coriaceous, upper surface dark green, under sides covered in red brown appressed tomentum; lamina margin somewhat sinuate, apex obtuse; base cuneate to attenuate. Inflorescence a lateral panicle of 210-220 capitula. Capitulum 10-12 mm long. Pedicel 7-15 mm long, densely invested in short fulvous hairs. Involucre cylindrical, bracts (30-)40-54, spiraled in 7-9 rows, light brown, recurved at maturity; outer bracts 1.5-2.6 x 0.8-1.4 mm, narrowly triangular, outer surface sparsely to moderately hairy, margins fimbriate. Florets 18-26 per capitulum. Ray-florets 10-15, pistillate; corolla glabrous, tube 2.7 mm long, ligulate with deflexed white limb 3.5-8 x 1.2-1.6 mm, 2-3-lobed at apex. Disc florets 8-11, hermaphrodite, corolla glabrous, white, tube 3.3. mm long, lobes 5, 1.5 x 0.6 mm. Seeds (cypselae) 1.7-3 x 0.4-0.5 mm, narrow-cylindric, brown, 5-6-ribbed, glabrous to sparsely hairy; pappus 3.5-4.5 mm, cream, finely scabrid.
Similar taxa
None. Well marked by the small tree habit, very large leaves with red-brown undersides, and the large number of involucral bracts. This last character it shares with O. pachyphylla Cheeseman, which is otherwise a much smaller shrub, with smaller leaves and capitula which have 1-3 ray florets.
Distribution
Endemic. North Island, Waima Forest, where it is known from the local high points of Hauturu, Te Raupua and Mt Misery.
Habitat
In cloud forest. Now primarily on cliff faces, although this habitat is probably not entirely natural - the cliffs are acting as refugia from goats and other browsing animals, which periodically plague the only known habitats of this species.
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.
- 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 Endangered | Qualifiers: DPS, DPT, RR
Threats
Severely threatened by animal browse, especially as this species is known from only four very small populations located within vulnerable ridges crests frequented by feral goats, cattle, horses and possums. Despite ongoing wild animal control, this species remains very vulnerable to even small numbers of these animals.
Detailed taxonomy
Genus
Family
Synonyms
Olearia crebra E.K.Cameron et Heenan
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November to January
Fruiting
January to April
Propagation technique
Difficult except in damp cool climates. Can be grown from semi-hardwood cuttings and fresh seed. Very susceptible to phytophora and verticillium wilt, and so prone to sudden collapse in gardens located within warm or humid climates.
Other information
Where To Buy
Not commericially available.
Chromosome number
2n = 108
Previous conservation statuses
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.
- 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.
2017 | Threatened – Nationally Endangered | Qualifiers: RR
2012 | Threatened – Nationally Endangered | Qualifiers: RR
2009 | Threatened – Nationally Endangered | Qualifiers: CD, RR
2004 | Threatened – Nationally Endangered
Referencing and citations
References and further reading
de Lange, P.J.; Heenan, P.B.; Norton, D.A.; Rolfe, J.R. & Sawyer, J.W.D. 2010: Threatened Plants of New Zealand. Canterbury University Press, Christchurch.
Heenan, P.B. & Cameron, E.K. 2002: A new species of Olearia from Waima Forest, Northland, New Zealand. New Zealand Journal of Botany 40(4): 535-542.
Saldivia, P.; Nicol, D.A. 2025: Reinstatement, broader circumscription, and infrageneric classification of Shawia (Astereae, Celmisiinae), a large woody genus endemic to Australasia. Phytoneuron 49: 1–43.
Attribution
Fact Sheet prepared for the NZPCN by P.J. de Lange 14 April (2006). Description by P.B Heenan (adapted from Heenan & Cameron 2002) and subsequently published in de Lange et al. (2010).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Shawia crebra Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/shawia-crebra/ (Date website was queried)