Hygrocybe reesiae (an agaric fungus) - vulnerable species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Hygrocybe reesiae A.M. Young, an agaric fungus, as a VULNERABLE SPECIES in Schedule 2 of the Act. The listing of vulnerable species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Hygrocybe reesiae A. M. Young (Fungi, Basidiomycota, Agaricales, Hygrophoraceae) is a small, lilac coloured gilled fungus. It is described by Young (1999): Pileus 10-20mm, convex but depressed at the centre to almost umbilicate when mature, smooth, dry, margins even and not splitting, pale lilac to lilac grey (near 16B3) but fading to buff when old (4B4-4A3). Lamellae deeply decurrent, distant, thick, 1 or 2 sets lamellulae, deep lilac to near violet (16B6), margins concolorous. Stipe 16-30 x 3-4mm, dry, smooth, cylindrical pallid lilac (16A30 but darker superiorly becoming buff (4B4 4A3), hollow. Spores (6) 6.5-9.0(-9.7)x4.5-6.8m m, mean 7.7x5.8m m, Q: 1.1-1.5, mean Q: 1.3-1.4, very broadly elliptical to almost subglobose, apiculus prominent, smooth, hyaline, non-amyloid, thin -walled. Basidia 50-60x(5.5-)6.5-9.5m m, mean 56x7.7m m, Q: 5.9-9.2, mean Q: 7.4, 4-spored, clamped and often approaching medallion clamps or medallion clamps present. Cystidia absent. Hymenophoral trama subregular to interwoven, composed of hyaline, thin-walled, occasionally branching elements, 20-60x3-7(-10)m m, only slightly constricted at the septa, but with abundant clamps some with medallion form, usually more irregular towards the margins. Pileipellis a cutis composed of an up to 10m m thick layer of very narrow, hyaline, clamped hyphae (some medallion clamps), 2-3m m diameter with the hyphal ends rounded, overlying a subparallel to interwoven subpellis of more inflated hyphae 2-9m m diameter, frequently septate and clamped at all septa, frequently branching. Stipitipellis a cutis of hyaline, thin-walled, clamped hyphae, 2-4m m diameter, medallion clamps present.

2. Hygrocybe reesiae A. M. Young is known in New South Wales only from its type locality in the Lane Cove Bushland Park in the Lane Cove Local Government Area in Sydney, and from the Blue Mountains National Park (Hazelbrook Area). It is also found in Tasmania.

3. Surveys in potentially suitable habitats elsewhere in the Sydney Basin Bioregion have failed to find Hygrocybe reesiae A. M. Young. At Lane Cove the species occurs on moss-covered banks under a closed canopy. The species does not produce basidiomes (above-ground fruiting structures) all year, but non-reproductive hyphal structures occur below ground.

4. Hygrocybe reesiae A. M. Young is likely to be threatened by water-borne pollutants. Industrial pollutants occur particularly in the upper reaches of Gore Creek in Lane Cove Bushland Park, and domestic contaminants arise from residential properties on the perimeter of the Park. The species is also likely to be at risk from encroachment by exotic weeds, dumping of rubbish and garden refuse, excess pedestrian traffic in areas where hyphae or basidiomes occur, and inappropriate bush regeneration measures that disturb the forest canopy and native understorey plants.

5. In view of points 2, 3 and 4, above the Scientific Committee is of the opinion that Hygrocybe reesiae A. M. Young is likely to become endangered unless the circumstances and factors threatening its survival or evolutionary development cease to operate.

Proposed Gazettal date: 19/07/02
Exhibition period: 19/07/02 - 23/08/02

Reference

Young, A.M. (1999). The Hygrocybeae (fungi, Basidiomycota, Agaricales, Hygrophoraceae) of the Lane Cove Bushland Park, New South Wales. Austrobaileya 5(3) 535-564