Astraeus species (false earthstar): A comprehensive review of taxonomy, ecology, nutritional value, therapeutic potential and conservation

Astraeus species, notably A. hygrometricus and A. odoratus, are vital ectomycorrhizal fungi in tropical forests, forming symbiotic associations with host trees such as Shorea robusta and Pinus kesiya. These interactions enhance nutrient cycling, soil health, biodiversity and carbon sequestration, contributing to overall forest resilience. Culturally, Astraeus mushrooms serve as important seasonal food and medicinal resources for indigenous communities. Morphologically distinct from true earthstars (Geastrum), Astraeus species possess a hygroscopic exoperidium that opens into a star shape, a defining feature of the genus within Diplocystaceae (Boletales). Recent molecular phylogenetic studies have expanded the genus, resolved taxonomic ambiguities and revealed new species diversity across Asia. Ecologically and economically, Astraeus mushrooms function as significant non-timber forest products with promising nutraceutical and pharmaceutical potential due to their bioactive compounds. However, threats from deforestation, overharvesting, habitat loss and climate change endanger their populations. This review synthesises knowledge on taxonomy, ecology, ethnomycology, nutritional and pharmacological properties and conservation challenges, emphasizing the need for integrated sustainable management and further research to unlock their full ecological, nutritional and therapeutical potential.