Weather earthstar  (Geastrum corollinum)

This species is classified as Vulnerable on the Pink List of British Plants 1994 (1).

Unlike other fungi, earthstars can move! With a strong tendency to absorb and lose water, their outer layers uncurl when it rains (2) (3). The fruit body of the weather earthstar is onion-shaped when closed but, when expanded, the outer layers split into 6 – 10 ‘star-like’ rays that curve outwards (2). The rays spread with enough force to push aside leaves, raising the inner spore-filled sac above surrounding debris. The rays close when they dry and the sac lowers (3). This species is pale brown with a whitish inner layer that, once exposed, eventually flakes off in patches (2).

WARNING: many species of fungus are poisonous or contain chemicals that can cause sickness. Never pick and eat any species of fungus that you cannot positively identify or are unsure about. Some species are deadly poisonous and can cause death within a few hours if swallowed.

The weather earthstar is found in Britain and Europe, but there have been few records of it in Britain since 1938. It was collected in Norfolk in 1782, remaining uncollected from then until 1895, when it was found in Hillingdon, Norfolk. It was found again in Maidenhead, Berkshire in 1896, Wensleydale, Yorkshire in 1908 and Hellesdon, Norfolk in 1938 (2).

Found on well-drained rich soil, usually in deciduous woods or in hedgerows with deciduous shrubs (2).

Fungi are neither plants nor animals but belong to their own kingdom. Unable to produce their own food through the process of photosynthesis as plants do, they acquire nutrients from living or dead plants, animals, or other fungi, by breaking down tissues and absorbing them. In many larger fungi (except lichens) the only visible parts are the fruit bodies, which arise from a largely unseen network of threads called ‘hyphae’. These hyphae permeate the fungus’ food source, which may be soil, leaf litter, rotten wood, dung, and so on, depending on the species, and take up nutrients (4). Earthstars are found from June to mid-September, during which the fruit body produces spores for reproduction (3).

The threats to this species are unknown.

No specific conservation action has been targeted at the weather earthstar.

For further information on the weather earthstar see:

Pegler, D. (1995) British puffballs, earthstars and stinkhorns: an account of the British gasteroid fungi. Royal Botanic Gardens, Kew.