Carmichaelia crassicaulis subsp. racemosa
Common names
slender coral broom
Biostatus
Native – Endemic taxon
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 Vulnerable | Qualifiers: Sp, DPS, DPT, RF
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Simplified description
Rare shrub with erect leafless blunt-tipped grooved branches. Branches 5mm in diameter, oval in cross section, grooves filled with white fuzz. Flowers small, pea-like, pale pink, streaked with purple. Fruit a small dry hairy pod with a long curved tip and containing 1-3 hard yellow seeds.
Flower colours
Cream, Violet/Purple
Detailed description
Lax, spreading to upright, leafless shrub up to 1.2 m. tall, with few, spreading, rather pliant subcylindric branches.Cladodes slender, wiry, 1.8-4.1 × 1.8-2.1 mm diameter, spreading with ascending tips, yellowish to yellow-brown, or grey, finely grooved. Leaves most present in seedlings and juveniles, absent on adults; lamina simple, obovate, suborbicular or oblong, 4.0-6.0 × 2.0-6.0 mm, upper and lower surfaces puberulent, glabrescent; apex emarginate or retuse; base cuneate; petiole puberulent, c.1.6 mm long. Leaves on cladodes reduced to a papery scale, triangular, glabrous, < 0.3 mm long; apex acute. Inflorescence 1 per node, in 1-6-flowered fascicles. Bracts broadly triangular, 0.4-0.9 mm long, pale green to hyaline, minutely hairy. Pedicel densely hairy, dark grey-green, 0.8-1.2 mm long. Calyx 4 × 3 mm, campanulate to narrowly turbinate; dark green to greenish brown flushed with red, outer surface densely invested in grey felted hairs. Calyx lobes 5, narrowly triangular, dark green flushed with red, 1.0-1.5 mm long, hairy, apex acute. Standard broadly obovate, initially patent, margins strongly recurved, 5-6 × 3-5 mm; centrally blotched purple, otherwise striped purple 10-16 times, margins cream. Wings broadly oblong, ± equal to keel, c.6 × 3 mm, basally blotched purple, purple striped 1-3 times, margins cream. Keel about 6 mm long, incurved, central portion purple, otherwise cream, often faintly striped purple. Stamens 5.5-6.0 mm long. Pistil exserted beyond stamens, 7-8 mm long. Pods ± orbicular to unequally deltoid, compressed, grey-brown to dark grey, outer surface densely covered in grey felted hairs, valves ± indehiscent, 6-8 × 5-8 mm; beak, stout, pungent, 0.6-1.0 mm long.
Similar taxa
Distinguished from coral broom (Carmichaelia crassicaulis subsp. crassicaulis) by the lax, spreading rather than stout, erect growth habit, slender, cladodes 1.8-4.1 × 1.8-2.1 mm diameter rather than 4.1-7.8 × 3.2-4.9 mm diameter in subsp. crassicaulis. Both subspecies have not been found growing together.
Distribution
Endemic. South Island (Canterbury (Mt Somers, Rangitata) Otago (Lindis Pass, western Otago (especially on the mountains around Lake Wakatipu).
Habitat
Montane to subalpine. Inhabiting sparsely vegetated greywacke and schist rock outcrops, small bluffs, talus slopes and colluvium, also within riparian shrubland.
Threats
Like the majority of South Island Carmichaelia slender coral broom is mostly threatened by the lack of regeneration. Most populations now comprise mature or senescent adults, and it is only in inaccessible sites such as gorges and cliff faces that seedlings and juvenile plants are seen. Slender coral broom is also highly palatable, and is often severely damaged by hares, rabbits, and at times sheep and goats.
Detailed taxonomy
Genus
Family
Synonyms
Corallospartium racemosum (Kirk) Ckn. et Allan, Corallospartium crassicaule var. racemosum Kirk
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
December to January
Fruiting
March to May
Propagation technique
Can be grown from seed and hardwood cuttings. However, cuttings can be very slow to strike. A slow growing plant suitable for a sunny site. Should be planted free draining soil.
Other information
Where To Buy
Not commercially available.
Etymology
carmichaelia: After Carmichael, a botanist
racemosa: Raceme bearing
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.
CARCSR
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 | Threatened – Nationally Vulnerable | Qualifiers: DP, RF
2012 | Threatened – Nationally Vulnerable | Qualifiers: DP, RF
2009 | Threatened – Nationally Vulnerable | Qualifiers: DP, RF
2004 | Data Deficient
Regional conservation statuses
Otago: 2025 | Regionally Threatened – Regionally Vulnerable | Qualifiers: DPR, DPS, NR, NStr, PF, RF, Sp, TL
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 “Conservation Status of Indigenous Vascular Plants in Otago, 2025” Jarvie S et al. (2025) report.
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, Christchurch, Canterbury University Press. 471pp
Attribution
Fact Sheet Prepared for NZPCN by: P.J. de Lange 28 October 2009. Description from de Lange et al. (2010).
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Carmichaelia crassicaulis subsp. racemosa Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/carmichaelia-crassicaulis-subsp-racemosa/ (Date website was queried)