Carmichaelia petriei
Common names
desert broom
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Yellowish shrub with untidy erect leafless branches. Branches rounded, 1–3.5 mm wide, with long yellow tips. Flowers small, pea-like, pink, in small clusters. Fruit a drooping dry pod containing 1–4 hard mottled seeds.
Flower colours
Violet/Purple, White
Detailed description
Sturdy, erect, wind-resistant, open habit branched shrub up to 2 m tall. Branches woody and stiff up to 100 mm diameter. Branchlets short and rigid about 100 × 3-4 mm, round or d-shaped in cross section, tips pointed often sharp to the touch, yellow-green to orange yellow. Leaves generally only a few on adult plants, 1-3 leaflets, covered in soft hairs, last leaflet can be 5 mm long, leaflets either side minute. Inflorescence of 1-3 short racemes per node, 3-9 flowered, on sparce to densely covered soft hair covered stalks. Flowers generally 6 × 5 mm, on very slim stout, soft-hair covered stems. Calyx bell-shaped, silky, 2-3 × 2 mm; teeth minute, pointed to sharply pointed. Petals - standard petals 5 × 6 mm, larger than the keel, light purple towards tip, paler at base, purple-veined; keel (fused central petals) 5 × 2 mm, greenish white, purplish towards tip, lobes rounded; wing petals 5 × 2 mm, pale, purplish towards tip, lobes rounded. Ovary glabrous. Pods swollen tear-drop shape, yellow green when early, when mature dark brown to black, 8-10 × 4 mm, hard, split either side of frame, often retaining seed(s), sharp beaked tip 3-6 mm long. Seeds 1-2 per pod, greenish yellow with black mottling or black, kidney shaped up to 3 mm long.
Similar taxa
May be confused with several other native broom species which it may be found growing near, the erect stout sharp branchlets are unique to this species.
Carmichaelia hollowayi maybe confused with the prostrate lower growing forms of this species, the blunt tipped pods of C. hollowayi can be used to distinguish from the sharp 3-6 mm beaked pod of. C. petriei
Distribution
Endemic New Zealand. South Island. Rainbow ski field to Catlins, most often found in central Otago and Canterbury.
Habitat
Lowland to montane grassland and open places.
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 | At Risk – Declining | Qualifiers: DPS, DPT, RF
Detailed taxonomy
Family
Synonyms
Carmichaelia petriei var. minor G.Simpson; Carmichaelia ramosa G.Simpson; Carmichaelia virgata Kirk
Taxonomic notes
In Allan (1961), a variant C. petriei var. minor is described, this is discussed in Heenan (1996), and explained as merely another form variation seen in this species. Heenan (1996) gives the example of the Waitaki River valley as a location where both forms may be seen growing side by side.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November - January
Fruiting
January – May (July)
Life cycle and dispersal
Seeds are possibly dispersed by wind and granivory (Thorsen et al., 2009).
Other information
Etymology
carmichaelia: After Carmichael, a botanist
petriei: Named after Donald Petrie (1846 -1925), Scottish born Otago botanist
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
CARPET
Chromosome number
2n = 32
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 | At Risk – Declining | Qualifiers: DP, RF
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Otago: 2024 | At Risk – Regionally Declining | Qualifiers: NStr, RF, TL
Referencing and citations
References and further reading
Allan, H. H. 1961. Flora of New Zealand. Vol. 1. Wellington: Government Printer. pg. 388.
Heenan, P.B. 1996: A taxonomic revision of Carmichaelia (Fabaceae - Galegeae) in New Zealand (part II). New Zealand Journal of Botany 34: 157-177.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
Wilson, H. D., & Galloway, T. 1993. Small-leaved shrubs of New Zealand. Manuka Press. Page 149.
Attribution
Fact sheet prepared for NZPCN by M.D. Ward (21 May 2024). Description from Allan (1961), Wilson & Galloway (1993).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.
NZPCN Fact Sheet citation
Please cite as: Ward, M.D. (Year at time of access): Carmichaelia petriei Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/carmichaelia-petriei/ (Date website was queried)