Note: This Determination has been superseded by the 2023 final determination for Carmichaelia exsul F.Muell – Critically Endangered Species listing.
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Carmichaelia exsul F.Muell. is described by Green (1994) as: a Broom-like shrub, 1-3 m tall. Adult shoots leafless, flattened, ridged, spreading and drooping. Leaves on juvenile shoots imparipinnate; leaflets 3-5, oblong to obovate, 0.7-2 (-3) cm long, 0.4-1.5 (-2.5) cm broad, apically rounded, emarginate. Inflorescence racemose, 2-5-flowered. Flowers white with purple markings, sweetly scented. Calyx somewhat obliquely campanulate, c. 2.5 mm long; teeth c. 0.5 mm long. Standard petal orbicular, 6-7 mm long; wings and keel c. 4-5 mm long. Pods ellipsoidal, flattened, 10-12 mm long, glabrous, with thickened margins; style persistent; dehiscing by two valves falling away leaving seed attached to replum. Seeds kidney-shaped, 3 mm long, pale orange.
2. Carmichaelia exsul is an endemic shrub from Lord Howe Island, where it is found in the southern mountains, generally around 300-500m above sea level. Carmichaelia is a genus of 40 species that is restricted to New Zealand except for this one species on Lord Howe Island.
3. Recent survey work (Hutton 2001, Hutton pers. comm.) suggests that C. exsul is known from less than twenty locations on Lord Howe Island. Very few individuals (1-20) are known from each location. The population occurs in the Permanent Park Reserve on Lord Howe Island.
4. Mature plants show evidence of damage by goats in the past, but this threat is not now likely to be an issue as goats have virtually been eradicated from the island. Weeds pose a threat to survival and recruitment in the species. Major weeds of concern are Ageratina adenophora (Crofton weed) and Pennisetum clandestinum (kikuyu). Other weeds at known sites include Lilium formosum, Bidens pilosa and Solanum nigrum. These weeds are often associated with exposed rocky areas that are the major habitat for Carmichaelia exsul, as well as with areas previously utilised by goats. The species is also threatened by demographic and environmental stochasticity due to its small population size.
In view of the above the Scientific Committee is of the opinion that Carmichaelia exsul F. Muell. is likely to become extinct in nature in New South Wales unless the circumstances and factors threatening its survival or evolutionary development cease to operate.
Proposed Gazettal date: 01/11/02
Exhibition period: 01/11/02 - 05/12/02
References
Green, P. (1994) Fabaceae.Flora of Australia 49, 172-197.
Hutton, I. (2001) Surveys of rare plants on Lord Howe Island - June 2001. Report to NSW Scientific Committee.