Astraeus Morgan, J. Cincinnati Soc. Nat. Hist. 12: 19-20 (1889). Type species: Astraeus hygrometricus (Pers.) Morgan, Journal of the Cincinnati Society of Natural History 12: 20 (1889) Description. Fruitbody 1.5-6 cm diam., sessile, with basal tuft of hyphae and arising from delicate rhizomorphs. Odour not distinctive. Exoperidium thick, stratified, hard and woody when dry. Endoperidial body subglobose, opening by an irregular, apical tear. Columella lacking. Paracapillitium hyaline, branched, mostly thick-walled, with clamp-connexions. Basidia capitate to broadly clavate, bearing 2-8 sessile spores. Basidiospores globose, 7-11 µm diam. (excluding ornament), dark brown, echinulate or verruculose, wall with 2-4 alternating electron-dense and electron-transparent layers (Sunhede, 1989). Habitat on soil, occurring in mycorrhizal association with woody plants. Distribution cosmopolitan.Fruitbodies of this genus closely resemble those of species of Geastrum, having an endoperidial body which is exposed at maturity by splitting of the exoperidium into rays which turn downwards to form a star-like pattern.