Zieria granulata (Illawarra Zieria) Recovery Plan
NSW Department of Environment and Conservation, 2005
ISBN: 1 7412 2143 9
3 Conservation Status
A review of the conservation status of Z. granulata was undertaken during the preparation of this recovery plan using the Endangered Flora Network (EFN) modified IUCN criteria (Keith et al. 1997). This review concluded that Z. granulata is appropriately listed as endangered as a consequence of the following factors:
- Restricted extent of occurrence;
- Severely fragmented distribution; and
- Continuing declines are predicted in habitat extent and quality, area of occupancy, and the number of locations that contain the species.
The genus Zieria belongs to the Rutaceae family and is predominantly located within eastern Australia. The distribution of the genus extends from NE Queensland to Tasmania and west to Kangaroo Island, with one species endemic to New Caledonia (Armstrong 2002). The genus Zieria contains 42 species and 10 infraspecific taxa (Armstrong 2002).
Z. granulata is a tall bushy shrub or small tree that can grow to six metres in ideal conditions. The entire plant is densely covered with glandular tubercles (small wart-like outgrowths). Very young branches are pubescent (ie they have fine short hairs) while older branches are virtually hairless. Leaves are palmately trifoliate (three-fingered), opposite and petiolate. The central leaflet is linear,
19.5 to 42.5 mm long, 0.5 to 1.5 mm broad with an obtuse apex. Leaf margins are revolute (downward curved) with a dull green upper surface and whitish lower surface. The inflorescence is axillary, shorter than the leaves and 50 to 180 flowered. Flowers are white, four petalled, and 3.5 to 4.5 mm in diameter. The fruit is a dry, light brown, glabrous (hairless) four-chambered capsule. Seeds are dark reddish-brown with a shiny black base, c. 2 mm long, c. 1.4 mm broad, and have an elaiosome (ant attracting appendage) (Armstrong 2002; M. Robinson, pers. comm.).