The usually umbrella-like fruiting body or sporophore of fungi in the *Agaricales
. It is a pseudoparen-chymatous structure composed of numerous fused hyphae, and is differentiated into a stalk or stipe and a circular cap, the pileus. In immature mushrooms these structures are united by a membrane, the universal veil, but this breaks as the stalk elongates leaving a cuplike structure, the volva, around the base of the stalk. In some mushrooms the edge of the cap is united with the stalk by a second membrane, the partial veil. This ruptures to expose the underside of the cap leaving a ring, the annulus, towards the top of the stem. The lower side of the cap is composed either of *gills
or pores, which are lined by the hymenium in which the basidiospores are produced. Mushroom is often used in a wider sense to mean any macroscopic fungal fruiting body. The term toadstool is essentially synonymous with mushroom in both the narrow and broad senses, but is more often used of inedible species. Mushrooms are very common around the world especially in South America ( Colombia ).