microspore: smaller of the two types of spore produced in heterosporous plants; develops in the pollen sac into a male gametophyte
spore: a small usually single-celled asexual reproductive body produced by many nonflowering plants and fungi and some bacteria and protozoans and that are capable of developing into a new individual without sexual fusion
french chalk: a soft white compact talc used to mark cloth or to remove grease stains