Caladenia tessellata (a terrestrial orchid) - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the terrestrial orchid Caladenia tessellata Fitzg. as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act, and, as a consequence, to omit reference to Caladenia tessellata Fitzg. from Schedule 2 (Vulnerable species) of the Act. Listing of endangered species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Caladenia tessellata Fitzg. (family Orchidaceae) is described by P. Bernhardt (1993) in Harden, G. (ed). Flora of New South Wales. UNSW Press. Vol. 4. p. 200 as: Terrestrial herb. Leaf linear to lanceolate, to 6 cm long and 5 mm wide, sparsely hairy. Inflorescence to 25 cm high, rarely >2-flowered, hairy. Sepals and lateral petals c. 2 cm long, cream-coloured with reddish stripes (lateral sepals often crossing); tails short, filiform or merely acuminate, with dark glandular hairs, less than a third of the length of the segments; tails of the lateral petals and lateral sepals often held stiffly and horizontally or petals deflexed. Labellum broad-cordate, 10-15 mm long, 10-20 mm wide, more or less unlobed, yellowish with a few darker striations; margins with thick, short, dark, teeth. Central calli thick and dark in 4-6 rows becoming crowded and overlapping towards the base and grading into short rows towards the apex. Column base with 2, prominent yellow glands. Flowers Sept.-Nov.

2. Within NSW, Caladenia tessellata is currently known from two disjunct areas; one population near Braidwood on the Southern Tablelands and three populations in the Wyong area on the Central Coast. The total population size is estimated to be less than 50 individuals.

3. The species is not known to occur within any conservation reserves.

4. There are continuing declines in the number of individuals and in the number of populations, with at least two populations becoming extinct since the 1980's and at least 14 populations in the Sydney and South Coast areas not recorded since the mid 20th Century.

5. Due to small population size, Caladenia tessellata is susceptible to catastrophic events and localised extinction. The species is also threatened by pedestrian activity and habitat degradation.

In view of the above the Scientific Committee is of the opinion that Caladenia tessellata Fitzg. 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: 13/12/02
Exhibition period: 13/12/02 - 31/01/03