Q.What is Sterigma?

Agaricus (Class Basidiomycetes, Order Agaricales, Family Agaricaceae) is the common field/button mushroom, growing on wood, manure and litter, sometimes in circular 'fairy rings'. Its life cycle shows three types of mycelium: primary mycelium (haploid, uninucleate, monokaryotic, arising directly from a germinating basidiospore), secondary mycelium (dikaryotic, formed when two primary mycelia of opposite strain fuse by somatogamy - the only form of sexual reproduction Agaricus shows, since it has no dedicated sex organs), and tertiary mycelium (found specifically in the fruiting body). The secondary mycelium forms rhizomorphs, which develop into the basidiocarp - the umbrella-shaped mushroom, made of a stipe (stalk, bearing a membranous annulus), a pileus (cap), and radiating gills on the underside. Each gill's fertile hymenium bears club-shaped basidia (interspersed with sterile paraphyses), eac …