Wilsonia backhousei (a perennial matforming subshrub) - vulnerable species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the perennial matforming subshrub, Wilsonia backhousei Hook. f. as a Vulnerable species on Schedule 2 of the Threatened Species Conservation Act. Listing is provided by for Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Wilsonia backhousei Hook. f. is a matforming prostrate member of the Convolvulaceae. It is described in the Flora of New South Wales (Harden, 1990) as: "Perennial subshrub with procumbent branches to c. 15 cm high more or less glabrous. Leaves linear-lanceolate to linear-obovate, 5 - 15, rarely to 20 mm long, 1 - 2 mm wide, apex acute, more or less fleshy, more or less glabrous; sessile. Flowers solitary. Calyx tubular, 5 - 7 mm long with short triangular lobes a third to a quarter the length of tube. Corolla white; tube c. 10 mm long; lobes linear-ovate to linear-elliptic, 2 - 4 mm long, acute. Style and stamens much exserted. Ovary 1- or 2-locular; style divided in the upper part into two branches; stigmas ovoid."

2. It often occurs as pure, or nearly pure, stands. At most sites, stands are limited in extent (in the order of a few 10s m.2 ). The most extensive stands occur around Jervis Bay.

3. Wilsonia backhousei is salt tolerant and is found in intertidal saltmarshes and, more rarely, on seacliffs.

4. In New South Wales Wilsonia backhousei is scattered along the coast, reaching a northern limit at Wamberal Lagoon.

5. In the Sydney region there has been a considerable decline in the abundance of the species this century, largely as a result of loss of habitat.

6. Mats of Wilsonia backhousei are damaged by trampling and vehicle use, and recovery from damage is slow.

7. Saltmarsh sites are subject to a number of other threats, including changed salinity regimes resulting from modified drainage or discharge of stormwater and invasion of weeds such as Juncus acutus.

8. In view of 5, 6 & 7 above the Scientific Committee is of the opinion that the species is likely to become endangered 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