Fungus (see below), which are produced by very closely related "Aspergilli". Quorn, a meat substitute, is made from "Fusarium venenatum". Edible mushrooms include commercially raised and wild-harvested fungi. "Agaricus bisporus", sold as button mushrooms when small or Portobello mushrooms when larger, is the most widely cultivated species in the West, used in salads, soups, and many other dishes. Many Asian fungi are commercially grown and have increased in popularity in the West. They are often available fresh in grocery stores and markets, including straw mushrooms ("Volvariella volvacea"), oyster mushrooms ("Pleurotus ostreatus"), shiitakes ("Lentinula edodes"), and enokitake ("Flammulina" spp.). Many other mushroom
Flat morphism is flat. Easy examples of this are elliptic fibrations, smooth morphisms, and morphisms to stratified varieties which satisfy miracle flatness on each of the strata. A simple non-example of a flat morphism is formula_8 This is because if we compute formula_9 we have to take a flat resolution of , and tensor the resolution with , we find that showing that the morphism cannot be flat. Another non-example of a flat morphism is a blowup since a flat morphism necessarily has equi-dimensional fibers. Let be a morphism of schemes. For a morphism , let and . "f" is flat if