diatom(redirected from Bacillariophyta)
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Related to Bacillariophyta: Bacillariophyceae
An individual of microscopic unicellular algae, the shells of which comprise a sedimentary infusorial earth.
[G. diatomos, cut in two]
diatom/di·a·tom/ (di´ah-tom) a unicellular microscopic form of alga having a cell wall of silica.
Any of various microscopic one-celled or colonial heterokonts of the class Bacillariophyceae that are photosynthetic, have a silica cell wall made up of two interlocking parts, and form an important component of phytoplankton.