Unknown Mushroom

These mushrooms had caps that ranged from 25 to 80 mm in width. They grew in a colony and were in different stages of maturation. The caps had a thin brown cuticle with small scaly flecks near the cap centre. They were undulating and folded and were very brittle. The flesh was pale (pic 3). The gills appeared to darken with age as can be seen in the photos. Gills might have had some forking ??. Stipes were short, pale and slightly furry. The base of the stipe of at least one young mushroom had a burst of mycelium (pic 5)