Plinthanthesis rodwayi (a grass) - endangered species listing

NSW Scientific Committee - final determination

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the grass Plinthanthesis rodwayi (C.E. Hubb.) S.T. Blake as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act, and as a consequence, to omit reference to Plinthanthesis rodwayi (C.E. Hubb.) S.T. Blake from Schedule 2 (Vulnerable species) of the Act. Listing of endangered species is provided for by Part 2 of the Act.

The Scientific Committee has found that:

1. Plinthanthesis rodwayi (C.E. Hubb.) S.T. Blake (family Poaceae) is described by S. W. L. Jacobs and K. L. McClay (1993) in Harden, G. (ed.). Flora of New South Wales. UNSW Press. Vol. 4. P. 558 as: Caespitose perennial to 0.5 m high. Leaves: ligule a ciliate rim with hairs c. 0.25 mm long; blade linear, rolled, upper surface and margins scabrous, glabrous. Inflorescence open, 6-8 cm long, 2-5 cm wide; rachis slender, usually flexuous, scabrous. Spikelets 5-6 mm long, gaping to 7 mm wide at maturity, bisexual florets 2, sometimes with 1 reduced floret above; pedicels slender, usually flexuous, 2-10 mm long, scabrous. Glumes 4-5 mm long, 3 nerved, keel minutely scabrous, glabrous. Lemmas 3-3.5 mm long, 8-nerved, awnless or with an awn in the sinus, lower half pilose with hairs <0.25 mm long, margins purplish brown, 2-lobed; lobes <1 mm long, subulate; awn, when present, slender, <0.5 mm long. Palea subequal to lemma, 2-keeled, keel scabrous, lower half pilose with hairs <0.25 mm long. Flowers spring-summer.

2. The species is a NSW endemic which was known from only two mountain tops within Budawang National Park in the 1930's - 1970s.

3. The species has not been relocated at these sites in recent years despite thorough surveys, and despite the species being noted as locally frequent in the late 1970s.

4. Although the exact cause of decline is unknown, proposed causes include; gross change in vegetation structure, grazing by macropods and the absence of fire.

In view of the above the Scientific Committee is of the opinion that Plinthanthesis rodwayi (C.E. Hubb.) S.T. Blakeis 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: 01/11/02

Exhibition period: 01/11/02 - 05/12/02

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Page last updated: 28 February 2011