Indicative distribution
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas.
(
click here to see geographic restrictions).
The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Caesalpinia bonduc
Gazetted date:
05 Dec 2003
Profile last updated:
14 Oct 2024
Description
Knicker Nut is a low, woody, scrambling shrub with sharp, recurved hooks on the leaf stems. It has large leaves that are divided (similar to a Poinciana) into 5 - 10 pairs of oblong to oval-shaped leaflets which are 2 - 4 cm long and have a sharp tip. The leaf stems are covered in sharp hooks. The flowers are yellow and grow in clusters up to 12 cm long. The brown, broad fruit pod is 8 cm by 4 cm, densely covered in spiny prickles, and splits open to reveal two greyish-white 15 mm seeds.
Distribution
Knicker Nut is only found in the northern part of Lord Howe Island, in the vicinity of Ned's Beach and near Old Settlement Beach. There are recent confirmed records of Knicker from Port Macquarie, South West Rocks and Yuraygir NP on the New South Wales North Coast. The species is distributed widely in the tropics and subtropics.
Habitat and ecology
- This species grows on sandy, coral-derived soil close to the shoreline, in coastal scrub vegetation, in full sun or light shade.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Invasion of habitat by weeds, particularly introduced grasses such as buffalo and kikuyu grass, as well as Asparagus and bitou bush.
- Accidental removal by bush regenerators.
- Deliberate removal due to the plant's prickly form.
- Risk of local extinction due to small population size.
- Climate change due to species' limited habitat area on Lord Howe Island.
- Introduction of disease.
- Predation and browsing by black rats.
- Invasion by weeds especially bitou bush.
- Poor knowledge of the species' abundance and distribution, particularly on the NSW mainland.
Recovery strategies
A Saving Our Species conservation project is currently being developed for this species and will be available soon. For information on how you can contribute to this species' recovery, see the Activities to assist this species section below.
Activities to assist this species
- Establish ex-situ collections in the event of local extinctions.
- Promote the conservation significance of Knicker Nut to ensure plants are not deliberately removed.
- Assist with exotic grass control on Lord Howe Island.
- Ensure Knicker Nut plants are protected when undertaking bush regeneration in habitat areas.
- Establish monitoring sites to enable early detection of impacts of climate change on Lord Howe Island.
- Support climate change initiatives.
- Study and monitor populations to determine this plant's biology.
- Research into ecology and genetics of species to provide information to assist in its conservation.
Information sources
- Auld, T.D. and Hutton, I. (2004) Conservation issues for the vascular flora of Lord Howe Island. Cunninghamia 8(4): 490-500
- Department of Environment and Climate Change NSW (2007) Lord Howe Island Biodiversity Management Plan. (DECC NSW, Sydney South)
- Green, P.S. (1994) Flora of Australia. Volume 49 Oceanic Islands 1. (Australian Government Press Service, Canberra)
- Hutton, I. (2001) Rare plant surveys Lord Howe Island. Report prepared for the NSW Scientific Committee, Sydney.
- Hutton, I. (2002) Field Guide to the Plants of Lord Howe Island. (Ian Hutton, Lord Howe Island)
- Lord Howe Island Board (2010) Lord Howe Island Permanent Park Preserve. Plan of Management. (Department of Environment, Climate Change and Water (NSW), Sydney)
- NSW Scientific Committee (2003) Caesalpinia bonduc (a scrambling shrub) - Endangered species determination - final.
- Wiecek, B. and McCune, S. (2002) Caesalpinia. Pp 366-7 in Harden, G.J. (ed.) Flora of New South Wales. Volume 2. Revised Edition (New South Wales University Press, Sydney)
|
IBRA Bioregion
|
IBRA Subregion
|
Known or predicted
|
Geographic restrictions region
|
|---|