Collared Earthstar.

Description:

An 'Earthstar' mushroom. Possibly 9 or 10 arms to the star although it's difficult to tell now since everything's covered in spores... 8cm across at its widest. About 8cm high, pale circle (about 5-8mm across) in the centre of the sporing body (3rd pic). In the middle of this circle is the opening where the spores 'puff' out. Going on rogersmushrooms.com species descroptions: Could be Geastrum triplex although no obvious 'collar' around spore sac. Could be G. rufescens but not sure about the spore sac being 'on a short indistinct stalk'. Ditiola on wildaboutbritain suggests microscopy (http://www.wildaboutbritain.co.uk/forums...). G. triplex spores are 3.5-4.5um whilst G rufescens are 3.0-4.5um

Notes:

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