Volvariella volvacea (also known as paddy straw mushroom or straw mushroom) is a species of edible mushroom cultivated throughout East and Southeast Asia and used extensively in Asian cuisine. They are often available fresh in regions where they are cultivated, but elsewhere are more frequently found canned or dried. Worldwide, straw mushrooms are the third-most-consumed mushroom.
In their button stage, straw mushrooms resemble poisonous death caps, but can be distinguished by several mycological features, including their pink spore print (spore prints of death caps are white). The two mushrooms have different distributions, with the death cap generally not found where the straw mushroom grows natively, but immigrants, particularly those from Southeast Asia to California and Australia, have been poisoned due to misidentification.
Straw mushrooms are grown on rice straw beds and are most commonly picked when immature (often labelled "unpeeled"), during their button or egg phase, and before the veil ruptures. They are adaptable, taking four to five days to mature, and are most successfully grown in subtropical climates with high annual rainfall. No record has been found of their cultivation before the 19th century.
In the finishing and aging process of making dark soy sauce, the broth of straw mushrooms can be mixed into the soy sauce, which is then exposed to the sun to make mushroom dark soy sauce ( cÃÂogà « lÃÂochà Âu). The added broth gives this soy sauce a richer flavor than plain dark soy sauce.
One cup () of straw mushrooms is nutritionally dense and provides of food energy, 27.7 üg selenium (50.36% of RDA), 699 mg sodium (46.60%), 2.6 mg iron (32.50%), 0.242 mg copper (26.89%), 69 üg vitamin B<sub>9</sub> (folate) (17.25%), 111 mg phosphorus (15.86%), 0.75 mg vitamin B<sub>5</sub> (pantothenic acid) (15.00%), 6.97 g protein (13.94%), 4.5 g total dietary fiber (11.84%), and 1.22 mg zinc (11.09%).