Caesalpinia bonduc (a scrambling shrub) - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the scrambling shrub Caesalpinia bonduc (L.) Roxb. as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act. Listing of endangered species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the scrambling shrub Caesalpinia bonduc (L.) Roxb. as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act. Listing of endangered species is provided for by Part 2 of the Act.

The Scientific Committee has found that:

1. Caesalpinia bonduc (L.) Roxb. (family Fabaceae) is a woody scrambling shrub, to c. 5m high, with large bipinnate leaves that have sharp recurved hooks on the underside. A full description can be found in Harden, G. J. (ed.) (2002)  Flora of NSW, Vol. 2, second edition, UNSW Press, Sydney, as follows: Scrambling shrub to c. 5 m high, more or less pubescent; prickles usually 1-6 mm long. Leaves 20-40 cm long, prickles scattered along leaf and pinnae rachises; pinnae 4-11 pairs, 5-20 cm long, leaflets 5-10 pairs, elliptic to oblong or ovate, mostly 15-40 mm long, 10-20 mm wide, apex acute to obtuse with a mucro, both surfaces more or less pubescent; petiole 5-10 mm long. Racemes axillary, often branched, 10-20 cm long, pubescent; pedicels 2-6 mm long, jointed. Sepals shorter than petals, pubescent. Petals 10-12 mm long, yellowish. Filaments 2-5 mm long. Pods oblong-elliptic, mostly 3-9 cm long, 25-40 mm wide, covered with bristly spines; seeds 1 or 2, ovoid to globose.

2. Caesalpinia bonduc is distributed widely in the tropics and subtropics. Within NSW it has only been found on Lord Howe Island and the far north coast of mainland NSW. There are no known records from north-eastern NSW since the 1890's, when it was collected from Tintenbar and Murwillumbah.

3. Caesalpinia bonduc is currently found on Lord Howe Island at 2 locations in the north of the island, on sandy soil close to the shoreline. Plants of  Caesalpinia bonduc that were previously recorded at a third location in the same vicinity could not be relocated in a recent survey. In 2001, one of the locations had 18 mature plants over an area of 0.24ha with a lone individual a further c.200m along the shore. The second location included only one individual (Hutton 2001).

4. The long term viability of the larger population may be threatened by the invasion of the habitat by weeds, particularly Buffalo Grass (Stenotaphrum secundatum), and Kikuyu grass ( Pennisetum clandestinum), which are forming dense swards beneath plants of  Caesalpinia bonduc (Hutton 2001). These weeds potentially limit the recruitment of seedlings of  Caesalpinia bonduc.  

5. In view of the above the Scientific Committee is of the opinion that Caesalpinia bonduc (L.) Roxb. is likely to become extinct in nature unless the circumstances and factors threatening its survival or evolutionary development cease to operate.

Associate Professor Paul Adam
Chairperson
Scientific Committee

Proposed Gazettal date: 05/12/03
Exhibition period: 05/12/03 - 06/02/04

Reference: 

Hutton I (2001) Rare plant surveys: Lord Howe Island. Report to NSW Scientific Committee, Sydney.