Carmichaelia compacta
Common name
Cromwell broom
Synonyms
Huttonella compacta (Petrie) Kirk; Carmichaelia compacta var. procumbens G.Simpson
Family
Fabaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Dicotyledonous Trees & Shrubs
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.
CARCOP
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | At Risk – Naturally Uncommon | Qualifiers: RR
Previous conservation statuses
2009 | At Risk – Declining | Qualifiers: DP, RF, RR
2004 | Range Restricted
Brief description
Small yellow-green shrub with many erect leafless twigs inhabiting the Central Otago gorges. Twigs oval in cross section, grooved. Leaves rare, sometimes in shaded parts, with 1-9 leaflets. Flowers small, pea-like, pink with slightly darker stripes, in erect clusters. Fruit a small dry flattened pod containing a single hard seed.
Distribution
Endemic. New Zealand: South Island (Central Otago (centred on the Kawarau and Cromwell Gorges and immediate surrounding area, also near Alexandra, Omakau, and Cromwell)
Habitat
A schist endemic. Colonising rock and debris slopes, rock outcrops, and associated steep tussock grassland, and river gorges.
Features
Erect or spreading shrub, up to 1-2 x 1-2 m, with densely placed branches and cladodes. Branches erect and spreading from base, 10-60 mm diameter. Cladodes linear, striate, compressed, erect to spreading, green, glabrous, often crowded at ends of branches, 60-220 x 1.5-2.5 mm; apex subacute, yellow; leaf nodes 4-9. Leaves 1-9-foliolate, fleshy, obovate or sometimes ovate, hairy; upper surface mottled; lower surface green; apex emarginate to retuse; margin hairy; leaflets sessile or with short petiolule, 1.5-7.0 x 1.0-6.5 mm; petiole hairy, 8-16 mm long. Leaves on cladodes reduced to a scale, triangular, glabrous, < 0.5 mm long; apex acute. Stipules clasping shoot, triangular, 0.4-0.5 x 0.4-0.5 mm; adaxial surface glabrous; abaxial surface hairy, becoming glabrous with age; apex subacute to obtuse; margin hairy. Inflorescence a raceme, 1 per node, each with 3-6 flowers. Peduncle glabrous to sparsely hairy, green, 7-16 mm long. Bracts triangular to narrow-triangular, pale green becoming membranous, 0.5-1 mm long; apex acute to subacute; margin hairy. Pedicel glabrous, pale green, 2-4 mm long. Bracteoles at base of receptacle or on upper part of pedicel, narrow rounded, white, c. 0.25 mm long; claw pale green, c.2 mm long. Stamens 3.0-3.5 mm long; lower filaments connate for c.¨þ length and with outside filaments free for 0.3-0.5 mm. Pistil exserted beyond stamens, c. 4 mm long; style with a ring of hairs below stigma; ovules 6-7. Pod obovate, broad at distal part, dorsally compressed, brown, pale grey, or straw-coloured, indehiscent, with inflated valves, 5.0-5.5 x 3.0-4.0 mm; beak on upper suture, slightly curved, stout, pungent, c.1 mm long. Seeds oblong-reniform, 1-2 per pod, light olive green or yellow-green with black mottling, 2.0-2.5 x 1.5-2.0 mm.
Similar taxa
Carmichaelia compacta is similar to C. curta Petrie and C. juncea Hook.f. from which it is distinguished by its more upright and shrubby habit, green and densely placed cladodes, large obovate pods, large seed, and the lower filaments being connate for c.¨þ of their length.
Flowering
October - February
Flower colours
Violet/Purple, White
Fruiting
December – July
Life cycle
Seeds are possibly dispersed by wind and granivory (Thorsen et al., 2009).
Propagation technique
Easily grown from seed and hardwood cuttings. Dislikes humidity. Best in a well drained, sunny situation. An attractive species that deserves to be more widely grown.
Threats
A narrow range endemic that is known from many sites but with an combined overall small population. Seedlings and juveniles are scarce, and there appears to be little recruitment. At accessible sites it is heavily browsed by sheep, goats, hares, and rabbits and these animals are probably the main reason for the lack of recruitment. Further, browsing pressure may be causing early senescence of older plants.
Etymology
carmichaelia: After Carmichael, a botanist
compacta: Small growing
Where To Buy
Not Commercially Available.
Attribution
Description from Heenan (1996)
References and further reading
Heenan, P.B. 1995: A taxonomic revision of Carmichaelia (Fabaceae - Galegeae) in New Zealand (part I). New Zealand Journal of Botany 33: 455-475
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 2009 Vol. 11 No. 4 pp. 285-309