Because of their widespread occurrence in water and in plant seeds such as dicots, the pseudomonads were observed early in the history of microbiology.
In microbiology and planktology, a theca is a subcellular structural component out of which the frustules of diatoms and dinoflagellates are constructed.
As this now-formalized nomenclature is not in harmony with the traditional usage familiar to specialists in microbiology and infectologists, the traditional nomenclature is common.
