Geastrales

 ( Basidiomycota Orders ) 

Geastrales is an order of puffballs Basidiomycota (fungi) that are related to Gomphales. The order contains the families Geastraceae, which includes the "earthstars" formerly placed in Lycoperdales or Phallales, and also Schenellaceae, Sclerogastraceae and Sphaerobolaceae.

About 160 species are classified in this order, divided among seven or eight genera, including Geastrum, Myriostoma and Sphaerobolus. Sphaerobolus species are known as "shotgun fungus" or "cannonball fungus". They colonize wood-based and may throw black, sticky, spore-containing globs onto nearby surfaces.

In Geastrum /ref> The basidiocarp of several earthstars are Hygrometer: in dry weather the rays will dry and curl up around the soft spore sac, protecting it. In this state, often the whole fungus becomes detached from the ground and may roll around like a tumbleweed. In wetter weather, the rays moisten and uncurl; some even curl backward lifting the spore sac up. This allows rain or animals to hit the spore sac, emitting when enough moisture is present for them to germinate and establish.