Diuris flavescens (a terrestrial orchid) - endangered species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Diuris flavescens D.L. Jones., a terrestrial orchid, 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.
This Determination has been superseded by the 2008 Determination - Critically endangered species listing.
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. The donkey orchid Diuris flavescens (Family Orchidaceae) was first described in 1993 by D.L Jones, from the north coast of NSW.
2. Diuris flavescens is a terrestrial herb. Leaves 2, linear, 8-17 cm long, 3-4 mm wide, conduplicate. Raceme 10-20 cm high, 1-5 flowered. Flowers pale yellow with dark brown markings on the dorsal sepal and labellum, c. 1.2 cm across. Dorsal sepal linear to ovate, 6-9 mm long, 4-5 mm wide, obliquely erect. Lateral sepals linear to oblanceolate, 12-18 mm long, 1.2-1.8 mm wide, deflexed, parallel or crossed. Petals obliquely erect, widely divergent, slightly recurved; lamina elliptic to nearly circular, 6-9 mm long, 4-5 mm wide; claw 4-6 mm long. Labellum 6-8 mm long; lateral lobes linear to more or less ovate, obtuse, often irregular, 2-3 mm long, 0.8-1.2 mm wide; midlobe ovate when flattened, 4.5-6.5 mm wide, ridged along midline; callus of 2 divergent, incurved ridges c. 5 mm long. Flowers Sept.-Oct. Grows in moist grassland in tall sclerophyll forest (Harden , 1993. Flora of NSW, Vol. 4. p.144).
3. The species is found only on the north coast of NSW. It is currently known from only 1 population, in the Wingham area.
4. A total of less than 50 plants is known and none occur in a reserve.
5. The species is threatened by over-mowing, use of weed spray, and collecting of plants. The risk of extinction is high due to low population numbers.
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 NSW unless the circumstances and factors threatening its survival cease to operate. Hence, Diuris flavescens is eligible to be listed as Endangered on Schedule 1, Part 1 of the Threatened Species Conservation Act.
Proposed gazettal date: 6/11/98
Exhibition period: 6/11/98 - 11/12/98