tetrasporangium

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

• noun A unicellular sporangium found in certain red algae in which four tetraspores are produced through meiosis.

from The Century Dictionary.

• noun In botany, a sporangium or cell in which tetraspores are produced.

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

• noun a sporangium containing four asexual spores