The Plant Kingdom (Plantae)

Plants provide nourishment for our bodies and souls. With the help of protists and fungi, plants provide the oxygen we breathe and the food that sustains us -- either directly or indirectly, by feeding other animals. Plants provide shade over our heads and cool carpets under our feet while surrounding us with beautiful colors and marking the change of seasons.

Prominent plants give us a handle on ecological communities. Descriptions such as "Redwood-Tanoak Forest" or "Oak Grassland" indicate not only the plants we may find there but the animals, fungi, and climate as well.

Classification of the plant kingdom can be especially confusing to the amateur naturalist. For example, according to modern botany:

• A palm tree has more in common with a blade of grass than with other trees.
• A strawberry plant is more closely related to an apple or apricot tree than to a clover or geranium.
• A Ginko (Maidenhair) tree is so different from other plants that it is in a phylum by itself. But if you have to group it with other plants, it belongs with conifers such as Pine trees.

At least four classification systems are in common use: Plants are classified into 12 phyla or divisions based largely on reproductive characteristics; they are classified by tissue structure into non-vascular (mosses) and vascular plants (all others); by "seed" structure into those that reproduce through naked seeds, covered seeds, or spores; or by stature divided into mosses, ferns, shrubs and vines, trees, and herbs.

All of these higher-level groupings are decidedly lopsided: the vast majority of the 270,000 plant species are flowering herbs.