Hygrocybe griseoramosa (an agaric fungus) - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list an agaric fungus Hygrocybe griseoramosa A. M. Young, R. Kearney & E. Kearney as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act. The 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. Hygrocybe griseoramosa (Fungi, Basidiomycota, Agaricales, Hygrophoraceae) is a small, buff to brown gilled fungus. It is described by Young  et al. (2001):  Pileus 20-30mm, sepia brown to chocolate brown at the centre but becoming light pinkish buff either as the surface dries or with age, convex becoming upturned and repand at the margins, striate when moist and fresh, dry, smooth, margins even.  Lamellae adnate with small decurrent tooth but then becoming apparently decurrent as the pileus becomes repand, grey, often extensively veined on the lamellae faces and on the pileus undersurface, frequently branching into two near the margins, margins even and concolorous.  Stipes 20-35 x 2-5mm, pallid to light grey, smooth but innately finely fibrillose, dry, solid but may become cavernous with age, tapered towards the base. No distinct odour present. Spore print white.  Spores 6.3-8.0 x 5.3-7.0(7.7) ìm, mean 7.4 x 6.0 ìm, Q: 1.04-1.5, mean Q: 1.24, very broad ellipsoid but mostly subglobose, globose or occasionally pyriform, smooth, hyaline, no reaction in iodine solution.  Basidia 42-57 x 7-8.5 ìm, mean 48.6 x 7.4 ìm, Q: (4.9-)6.0-7.5, mean Q: 6.57, 4-spored but occasionally with scattered 2-spored basidia, clamps present.  Cystidia absent.  Hymenophoral trama more or less regular near the pileus becoming subregular near the centre and irregular near the margins of the lamellae, composed of chains of cylindrical or ellipsoid to long ellipsoid elements tht are thin-walled, hyaline, inflated 22-117 x 5-20 ìm, clamps present.  Pileipellis a cutis of repent, hyaline, thin-walled, septate hyphae 3-10 ìm, clamps present; pigment granules present on the hyphae surface.  Stipitipellis a cutis of repent, hyaline, thin-walled, septate hyphae 2.5-5 ìm, clamps present.

2. Hygrocybe griseoramosa is known only from its type locality in Lane Cove Bushland Park in the Lane Cove local government area in Sydney.

3. Surveys  in potentially suitable habitats elsewhere in the Sydney Basin Bioregion have failed to find  Hygrocybe griseoramosa. The occurrence of this species in the Lane Cove Bushland Park appears to be very limited. The species does not produce basidiomes (above-ground fruiting structures) all year, but non-reproductive hyphal structures occur below ground.

4. Hygrocybe griseoramosa 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.

In view of points the above the Scientific Committee is of the opinion that  Hygrocybe griseoramosa  A. M. Young, R. Kearney & E. Kearney 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: 20/12/02
Exhibition period: 20/12/02 - 07/02/03

Reference:

Young, A.M., Kearney, R. & Kearney, E. (2001). Additions to the Hygrophoraceae of Lane Cove Bushland Park. Australasian Mycologist 20, 79-86.