straw mushroom

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An edible mushroom (Volvariella volvacea) having a white cap and a swollen base, cultivated especially in East and Southeast Asia and typically harvested when immature.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A small, edible mushroom used primarily in the cuisines of East and Southeast Asia, Volvariella volvacea

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun small tropical and subtropical edible mushroom having a white cap and long stem; an expensive delicacy in China and other Asian countries where it is grown commercially