Home » Gardening Information » Garden Botany
Plant Classification
Plant classification is an attempt to organize the hundreds of thousands of species of plants into a meaningful scheme that allows us to make assumptions about the life history, biology, and chemical constituents of various groups. The International Code of Botanical Nomenclature, the rules that govern the naming of plants, currently recognizes seven ranks. Each of these ranks is included in one (and only one) higher rank and has one or more members of subordinate rank.
The complete classification of corn, for example, with the names of each of the seven ranks of corn is:
Kingdom: Plantae
Division: Magnoliophyta
Class: Liliopsida
Order: Cyperales
Family: Poaceae
Genus: Zea
Species: Zea mays
The way corn is classified at each of these seven ranks indicates something about the plant. The kingdom Plantae indicates that corn is a plant and probably photosynthesizes using chlorophyll. The division Magnoliophyta indicates that it is a flowering plant. The class Liliopsida indicates that corn is a monocot—that is, it has one cotyledon (the first leaf formed on a seedling) and leaves with parallel veins, and its flower parts occur in multiples of three (three or six petals, three or six stamens, and so on). The order Cyperales indicates that the seeds store starch and the flowers lack petals and sepals. The family Poaceae indicates that it has a unique type of inflorescence, round stems, and a distinctive internal anatomy. And so on, down to the species level.
The highest rank for living organisms is the kingdom. For many centuries, living organisms were grouped into one of two kingdoms—plant or animal. Only in the past several decades have new classifications arisen; with new discoveries and new understanding of life, this undoubtedly will continue to change. Today, the most widely accepted classification recognizes five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia.