Plants are extremely complex and diverse, and there are millions of different plant species— some that haven’t even been fully discovered and studied yet! In order to continue the study and organization of plants, botanists (scientists who study plants) must find a way to categorize the many different species. While all plants are made up of similar parts that are essential in maintaining their survival (i.e. having roots, stem, leaves, etc.), they often look different. These differences in characteristics are used to group plants into species, which provides a way of classifying and therefore organizing plants.
While there are many ways to structure plant classification, one way is to group them into vascular and non-vascular plants, seed bearing and spore bearing, and angiosperms and gymnosperms. Plants can also be classified as grasses, herbaceous plants, woody shrubs, and trees.
vascular: plants that use roots and stems to take in water and nutrients (refer to lesson 1 in Unit 3)
non-vascular: plants that don’t use roots and stems
angiosperms: also known as flowering plants; all have seeds that are protected by an ovule (think of an apple or other fruit).
gymnosperms: a term meaning “naked seed;” refers to plants with seeds that aren’t protected by an ovule. Examples are conifers, which have pinecones.
grasses: plants that have slender leaves and reproduce by sending out underground stems called rhizomes that usually grow horizontally
herbaceous plants: those with leaves and stems that die at the end of the growing season
woody shrubs: plants that have stems that are covered by a layer of bark
trees: woody shrubs that have a main trunk and many branches