Caladenia porphyrea - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Caladenia porphyrea D.L. Jones, an orchid, as an ENDANGERED SPECIES on Part 1 of Schedule 1 of the Threatened Species Conservation 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 porphyrea D.L. Jones (family Orchidaceae) is an endemic Australian orchid that has been described by Jones (1999) as follows:

"Hirsute, terrestrial herb growing singly or in small groups. Leaf narrowly linear, 15-25 cm long, 0.25-0.45 cm wide, erect, dark green, base reddish, apex acute; trichomes sparse, c. 0.7 mm long, transparent, glandular, patent. Scape 20-35 cm tall, very slender, wiry, densely covered with glandular trichomes similar to those on the leaf. Sterile bracts closely sheathing, oblong-obovate, 8-12 mm long, 3-4 mm wide, subacute, externally hirsute. Floral bracts closely sheathing, narrowly oblong, 6-7 mm long, 3-3.5 mm wide, obtuse, externally hirsute. Flower solitary, 30-40 mm diam., usually bright pink to purplish pink internally, occasionally white, externally greenish white to brownish purple; labellum white, pink or purplish, heavily barred with reddish purple, the apex orange; basal calli orange, rest white; column greenish, heavily stained and barred with red; floral odour undetectable. Tepals moderately glandular externally, lacking a central dorsal band; dorsal sepal erect to shallowly recurved; lateral sepals porrect to obliquely decurved, slightly divergent; petals widely spreading. Dorsal sepal narrowly elliptic to narrowly obovate, 13-16 mm long, 3-4 mm wide, internally glabrous, subacute. Lateral sepals lanceolate, 17-20 mm long, 5-6.5 mm wide, internally glabrous, subacute. Petals lanceolate, 16-19 mm long, 3.5-5 mm wide, acute to acuminate. Labellum hinged at the base. Lamina prominently 3-lobed, 8-11 mm long, 8-10 mm wide, erect in the proximal third then curved forwards; apex recurved; lateral lobes c. 3.8 mm wide, erect but not column-embracing, entire; mid-lobe ovate-deltate, 2-5.4 mm long, c. 3.5 mm wide; marginal calli 4-6 pairs, to 1 mm long, narrowly linear, straight or curved. Lamina calli in 2 rows, extending to the base of the mid-lobe, the basal calli distinct from the rest; basal calli 6 or 8, c. 2.3 mm long; stalk c. 1 mm long, white; head ovoid, c. 1.8 mm long, orange; main lamina calli 8 to 12 pairs, crowded, white, the apex of distal ones hooked forwards; longest lamina calli c. 1.4 mm

long; stalk c. 1 mm long, white; head clavate. Column 9.5-11 mm long, c. 3.5 mm wide, porrect from the ovary, narrowly winged; central ridge 1 mm wide. Anther c. 2.3 mm long, 1.6 mm wide, green, densely papillate; rostrum prominent. Pollinia 4, c. 1.7 mm long, roughly deltate in shape, deeply lobed, white, mealy. Stigma more or less circular, c. 1.8 mm wide, sunken, green. Capsule not seen."

2. In NSW, Caladenia porphyrea has a highly restricted geographic distribution. It has been recorded from 2 localities in the Wyong local government area c. 2 km apart. At these locations it covers areas of c. 2 ha and 0.2ha respectively. A specimen from Springbrook, Queensland, purported to be  Caladenia porphyrea, is unlikely to represent the same taxon as the NSW populations (D.L. Jones pers.comm).

3. The estimated total number of mature individuals of the species is low. The largest population is estimated to comprise fewer than 600 plants. Since its discovery however, at least 60 tubers have been removed illegally. The second, smaller population comprises c. 40 plants.

4. Threats affecting the NSW populations include illegal collection and removal of tubers, excavation of tubers by bandicoots and a decline in habitat quality caused by competition from invasive weeds such as Chrysanthemoides monilifera and  Lantana camara, and soil disturbance from trail bikes and occasional other motor vehicle activity. The populations are further threatened by demographic and environmental stochasticity due to their small size and area of occupancy. It may be inferred from these threats that  Caladenia porphyrea is suffering a continuing decline or will suffer a projected decline in abundance, geographic distribution or habitat quality.

5. Caladenia porphyrea D.L. Jones is eligible to be listed as an endangered species as, in the opinion of the Scientific Committee, it is facing a very high risk of extinction in New South Wales in the near future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Amendment (Listing Criteria) Regulation 2005:

Clause 14

The species has undergone, is observed, estimated, inferred or reasonably suspected to have undergone, or is likely to undergo within a time frame appropriate to the life cycle and habitat characteristics of the taxon:

(b) a large reduction in population size,

based on either:

(d) an index of abundance appropriate to the taxon, or

(e) geographic distribution, habitat quality or diversity, or genetic diversity.

Clause 15

The geographic distribution of the species is estimated or inferred to be:

(b) highly restricted,

and either:

(d) a projected or continuing decline is observed, estimated or inferred in either:

(i) an index of abundance appropriate to the taxon, or
(ii) geographic distribution, habitat quality or diversity, or genetic diversity

Clause 16

The estimated total number of mature individuals of the species is:

(b)low,

and either:

(d) a projected or continuing decline is observed, estimated or inferred in either:

(i) an index of abundance appropriate to the taxon, or
(ii) geographic distribution, habitat quality or diversity, or genetic diversity.

Associate Professor Lesley Hughes
Chairperson
Scientific Committee

Proposed Gazettal date: 21/07/06
Exhibition period: 21/07/06 - 15/09/06

References

Jones DL (1999) Eight new species of Caladenia (Orchidaceae) from eastern Australia. The  Orchadian 13, 4-24.