Diuris sp.Oaklands (D.L. Jones) (an orchid) - endangered species listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Diuris sp. (Oaklands, D.L Jones 5380), an orchid, as an ENDANGERED SPECIES on Part 1 of Schedule 1 of the Act. Listing is provided by Part 2 of the Act.
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Diuris sp. (Oaklands, D.L Jones 5380) (Orchidaceae) is found in southern NSW and has recently been distinguished from Diuris fragrantissima occurring in Victoria by D.L. Jones. Jones states Diuris sp. (Oaklands, D.L Jones 5380) is "allied to Diuris fragrantissima but much more robust with larger leaves; scape to 50 cm tall cf. 20 cm; flowers up to 9 per scape cf. 6; flowers slightly fragrant cf. intensely fragrant with a strong spicy scent; longer lateral sepals; and, a larger column; significant habitat differences." Diuris sp. (Oaklands, D.L Jones 5380) is referred to as the NSW population of Diuris fragrantissima in Tony Bishop's book Field Guide to the Orchids of NSW and Victoria (University of NSW Press, 1996).
A full description of Diuris sp. (Oaklands, D.L Jones 5380) is given below.
2. Diuris sp. (Oaklands, D.L Jones 5380) is currently known from the Oaklands-Urana region of southern NSW growing in Callitris glaucophylla woodland, either among dense grass in flat areas with associated Eucalypts or amongst sparse grass and forbs on low sandhills. Soils are mostly sandy loam.
3. There are thought to be 6-7 populations of Diuris sp. (Oaklands, D.L Jones 5380). Population numbers are low (20-150 plants) in four of the populations where estimates have been made.
4. Diuris sp. (Oaklands, D.L Jones 5380) occurs in a largely agricultural area with some plants occurring on a roadside, and no population is protected in a formal conservation reserve. Diuris sp. (Oaklands, D.L Jones 5380) may be threatened from road maintenance activities, and is at risk due to the impact of chance events on low population numbers and the low number of individuals in each population.
5. In view of 3, and 4 above the Scientific Committee is of the opinion that Diuris sp. (Oaklands, D.L Jones 5380) 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: 09/02/01
Exhibition period: 09/02/01 - 16/03/01
Description of Diuris sp. (Oaklands, D.L Jones 5380) taken from Jones ms
Tuberous terrestrial herb growing singly in loose scattered groups. Tubers more or less obovoid, bilobed to palmate, 15-35 mm long, 10-25 mm wide, fleshy, brown. Leaves basal, lax, 2-3, linear to linear-lanceolate, 15-35 cm long, 5-9 mm wide, convolute, green; base sheathing; apex acute to acuminate. Scape 30-50 cm tall, stout, 3-9-flowered. Sterile bracts 2, narrowly ovate-lanceolate, 4-12 cm long, 5-9 mm wide, acute to acuminate, closely sheathing; lowest bract sometimes extended and leaf-like. Fertile bracts narrowly ovate-lanceolate, 3-7 cm long, 2-5 mm wide, acute to acuminate, closely sheathing. Pedicels 10-45 mm long, very slender. Ovaries obovoid, 4-8 mm long, 2-4 mm wide. Flowers porrect, c. 25-35 mm diam., slightly fragrant, whitish, mauve or purple, often marbled and striped with darker markings, the labellum usually darker than the rest and often with prominent interrupted striae. Dorsal sepal porrect in the proximal half then obliquely erect, ovate to ovate-elliptic, 10-20 mm long, 8-12 mm wide; apex broadly obtuse to apiculate. Lateral sepals obliquely deflexed, narrowly linear, 4-12 cm long, 2-4 mm wide, more or less parallel; margins involute; apex asymmetrically acute to acuminate. Petals erect, slightly divergent; lamina narrowly to broadly ovate to elliptic, 6-16 mm long, 6-10 mm wide, tapered basally into the claw; apex obtuse; claw 4-10 mm long, curved, green to brownish, widest near the apex, tapered to the base. Labellum 10-15 mm long, obliquely decurved, deeply 3-lobed; lateral lobes erect, oblong-cuneate, 3-6 mm long, 1-3 mm wide, shallowly curved; outer margins entire to slightly irregular; mid-lobe transversely ovate-reniform to flabelliform, 10-15 mm long, 8-15 mm wide, with a central longitudinal fold; margins slightly irregular; apex obtusely apiculate. Labellum callus glabrous, whitish marked with mauve or purple, well-developed on the labellum base and on the basal part of the mid-lobe, consisting of 2 raised divergent ridges which incurve slightly at the apex, with an ill-defined central tapered ridge extending well onto the mid-lobe. Column porrect from the end of the ovary, 5.5-6 mm long, 4-4.5 mm wide. Column wings more or less lanceolate, c. 6 mm long, c. 1.5 mm wide, irregularly toothed. Anther narrowly ovate, c. 5.5 mm long, c. 2.8 mm wide, brownish purple. Pollinarium c. 4.5 mm long, c. 2.4 mm wide; viscidium elliptic, c. 1 mm long; pollinia clavate, c. 4 mm long, white, mealy. Stigma broadly cordate, c. 2.5 mm long, c. 4 mm wide. Capsules ovoid to obovoid, 8-11 mm long, 4-6 mm wide, erect. Flowering period November-December.