Corunastylis sp. Charmhaven (NSW896673) - provisional listing of a critically endangered species

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Determination for provisional listing, on an emergency basis, of the species Corunastylis sp. Charmhaven (NSW896673) as a CRITICALLY ENDANGERED SPECIES in Part 1 of Schedule 1A of the Act. Provisional Listing of Critically Endangered species on an emergency basis is provided for by Part 2 of the Act.

NSW Scientific Committee - provisional listing

The Scientific Committee has found that:

1. Corunastylis sp. Charmhaven (NSW896673) (Orchidaceae) is a terrestrial orchid described by Weston ( in litt. 2012) as: “Terrestrial tuberous herb. Leaf 19.5 cm long, 1.8 mm wide, slender, terete, [colour mostly unknown]; lamina 16 mm long (measured from base of terete part; 25 mm from tip to base of slit), 1.4 mm wide, subulate, sheathing the scape, ending 8.5 mm above base of the first flower. Inflorescence 20.5 cm tall, bearing 9 flowers (6-7 in photos) in a well-spaced spike, 1.4 cm long; rachis deep red-brown. Flowers c. 8.5 mm between tip of dorsal sepal and tips of lateral sepals, 6 mm between tips of lateral petals, green and cream with deep maroon markings, semi-erect to erect. Ovary 2.7-3.8 mm long, ellipsoidal, curved. Dorsal sepal 4.0-4.5 mm long, 2.0-2.1 mm wide, ovate, cucullate, glabrous, greenish cream, with 3 maroon veins and maroon margins. Lateral sepals 5.0-5.5 mm long, 1.3-1.4 mm wide, narrow-ovate, bent abaxially c. 1 mm above base through 45º -100º, erect to ascending, slightly to prominently divergent, distally involute, green with heavy reddish suffusion in basal 1/2 to 2/3, glabrous. Lateral petals 3.5-3.7 mm long, 1.0-1.2 mm wide, narrow-ovate, acute or shortly acuminate, divergent, cream with 3 maroon veins and maroon margins, with sparsely ciliate margins; cilia mostly less than 0.1 mm long. Labellum 3.2 mm long, 1.5 mm wide, obovate, rounded distally, with recurved, mucronate apex, maroon, narrowed in proximal 2/3, thick and fleshy, the margins densely cilaite [sic] with trichomes varying in length from

2. Corunastylis sp. Charmhaven (NSW896673) is a recently described species. It is similar to  Corunastylis archeri (syn.  Genoplesium archeri) but differs from C. archeri in having fewer, larger flowers (6-9 flowers, 6 mm across, versus 10-20 flowers, 4.5–5 mm across in  C. archeri), borne on a shorter inflorescence (1.4 cm long versus 2–3.5 cm long in  C. archeri) (Weston pers. comm. Aug 2012).

3. Corunastylis sp. Charmhaven (NSW896673) is currently only known from the Wyong Shire of NSW where it is restricted to a single location in the Gorokan / Charmhaven area. It occurs within low woodland to heathland with a shrubby understorey and ground layer. Dominants include  Allocasuarina littoralis, Leptospermum juniperinum,  Melaleuca nodosa, Callistemon linearis and  Schoenus brevifolius.

4. The number of mature individuals of Corunastylis sp. Charmhaven (NSW896673) is very low, with less than 20 plants occurring in the only known population. This population is under threat from clearing for development and from rabbits grazing on the tubers and flowers. ‘Clearing of native vegetation’ and ‘Competition and grazing by the feral European Rabbit,  Oryctolagus cuniculus (L.)’ are listed as Key Threatening Processes under the  Threatened Species Conservation Act 1995.

5. The geographic distribution of Corunastylis sp. Charmhaven (NSW896673) is very highly restricted. The area of occupancy and extent of occurrence were estimated to be 4 km². The area of occupancy was equivalent to a single (2 km x 2 km) grid, the recommended measure for AOO in the IUCN (2011) guidelines. By having a very highly restricted geographic distribution and occurring at only one location, Corunastylis sp. Charmhaven (NSW896673) is prone to the effects of human activities or stochastic events within a very short time period in an uncertain future.

6. Corunastylis sp. Charmhaven (NSW896673) is eligible to be listed as a Critically Endangered species as, in the opinion of the Scientific Committee, it is facing an extremely high risk of extinction in New South Wales in the immediate future as determined in accordance with the following criteria as prescribed by the  Threatened Species Conservation Regulation,  2010:

Clause 7 Restricted geographic distribution and other conditions

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

(a) very highly restricted,

and:

(d) a projected or continuing decline is observed, estimated or inferred in either of the key indicators,

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

(b) the geographic distribution, habitat quality or diversity, or genetic diversity.

Clause 8 Low numbers of mature individuals of species and other conditions

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

(a) very low,

and:

(d) a projected or continuing decline is observed, estimated or inferred in either of the key indicators,

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

(b) the geographic distribution, habitat quality or diversity, or genetic diversity.

Clause 9 Low number of mature individuals of species  

The total number of mature individuals of the species is observed, estimated or inferred to be:

(a) extremely low

7. Corunastylis sp. Charmhaven (NSW896673) is eligible to be provisionally listed in Part 1 of Schedule 1A as a Critically Endangered species as, in the opinion of the Scientific Committee:

(a) the species:

(i) although not previously known to have existed in New South Wales, is believed on current knowledge to be indigenous to New South Wales; and

(b) the species is not listed in Part 1 of Schedule 1 or 1A.

Associate Professor Michelle Leishman
Chairperson
Scientific Committee

Proposed Gazettal date: 05/10/12

Exhibition period: 05/10/12 – 30/11/12

References:

IUCN Standards and Petitions Subcommittee. 2011. Guidelines for Using the IUCN Red List Categories and Criteria. Version 9.0. Prepared by the Standards and Petitions Subcommittee.