It's often used in scientific terms, especially in botany, to refer to plants in general or a specific group of plants. For example:
* Phytoplankton: Microscopic plants that live in water.
* Bryophyta: A division of non-vascular plants, including mosses, liverworts, and hornworts.
* Angiospermophyta: A division of flowering plants.
So, whenever you see "phyta" in a word, it's a good indicator that the term relates to plants in some way.