straw mushrooms Volvariella volvacea, sometimes called paddy straw mushrooms, have been cultivated for centuries in China and SE Asia. They are grown outdoors on bundles of wetted rice straw and are usually gathered while still young and small. A full-sized mushroom is up to 8 cm (3") across the cap, which is conical, white, and has a darker top. The stem may reach 12 cm (5") long and 2 cm (0.75") thick, and is a streaky off-white. There is no ring, but there is a large volva (cup-shaped sheath) at the base. The gills, at first white, become pink when older.
