tetraspore

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

• noun One of four spores produced from a tetrasporangium.

from The Century Dictionary.

• noun In botany, an asexually produced spore of florideous algæ: so called from the circumstance that usually four are produced by the division of the mother-cell. See spore, cruciate, 2, bispore, Florideæ. Also called spherospore. See cut under Algæ.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Bot.) A nonsexual spore, one of a group of four regularly occurring in red seaweeds.

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

• noun biology Any of the four, asexual spores produced by a sporangium

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

• noun one of the four asexual spores produced within a sporangium