Wilsonia rotundifolia (a perennial dwarf subshrub) - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the perennial dwarf subshrub Wilsonia rotundifolia Hook., as an ENDANGERED SPECIES on Part 1 of Schedule 1 of the Threatened Species Conservation Act. Listing is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Wilsonia rotundifolia Hook., a very dwarf subshrub, is a member of the Convolvulaceae. It is salt tolerant and occurs in coastal saltmarshes and inland saline sites. It is described in the Flora of New South Wales (Harden, 1990) as: "Perennial subshrub with prostrate stems, more or less hirsute with spreading hairs. Leaves from broad-ovate with acute apex to oblong-spathulate with obtuse apex, 1.5 - 4 mm long, sessile or shortly petiolate. Flowers solitary. Calyx tubular, 4.5 - 5 mm long with short triangular teeth a third as long as tube. Corolla white; tube more or less equal to the calyx; lobes oblong-elliptic, 2 - 3 mm long, bluntly acute. Style and stamens slightly exserted. Ovary completely or partially 2-locular; style divided at or below the middle into two branches; stigmas capitate."

2. In coastal New South Wales it is known from four coastal populations at Lake Wollumboola, Swan Lake, Meringo Lagoon and Lake Coila. The total number of plants in coastal sites is only a few hundred. It occurs in mid marsh, mixed with Sporobolus virginicus and Sarcocornia quinqueflora. In inland New South Wales there are records from a number of saline sites (Lake Bathurst and the Deniliquin-Barham district).

3. Trampling, by humans or cattle, results in stem breakage.

4. One coastal population is potentially threatened by urban development.

5. Given the small number of locations and disturbance to these sites, Wilsonia rotundifolia meets the criteria for listing as an endangered species.

6. In view of 3, 4 & 5 above the Scientific Committee is of the opinion that the species 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: 15/9/00
Exhibition period: 15/9/00 - 20/10/00