These jolly mushrooms are called Volvariella volvacea. Their common name comes from the rice straw on which they are grown. The straw mushroom, also called paddy straw mushroom, is cultivated in the hot, steamy climate of Southeast Asia. Attempts to grow them in the southern United States so far have been unsuccessful. They are not widely eaten in the United States, but worldwide they rank third in consumption, just behind Agaricus bisporus (the common store mushroom) and Lentinus edodes (shiitake). Indeed, straw mushrooms have been used for food in China for two thousand years. Baskets of fresh straw mushrooms can be found in the exotic marketplaces of southern China and Asia. They look like tan quail eggs. They are harvested in the egg stage before the caps have erupted from their confining universal veils. When sold in this condition they are called unpeeled. Research has shown that these unopened caps contain a more nutritious balance of amino acids than when opened, suggesting that these mushrooms could supplement proteins lacking in the Asian diet. That is why this mushroom is seldom found peeled, or in its mature state with the cap open.