The Geastrales contain a single family, the Geastraceae. The geastrum genus includes fruiting bodies commonly referred to as ‘earth stars’. Being hygroscopic, their outer shell opens like a flower in wet weather conditions, sometimes curling under and raising the spore sac which is perforated at the top so that rain drops cause the release of spores ready to germinate provided there is sufficient moisture. In dry weather, the outer covering closes up to protect the spore sac.

To see enlarged photos of each fungus represented in this order, click on the first photo and then click on the textual links above each photo to get to the next one.