In botany, flora (plural: floras or florae) has two meanings: a flora (with a lower case ‘f’) refers to the plant life occurring in a particular region, generally the naturally occurring or indigenous plant life, while a Flora (with a capital ‘F’) refers to a book or other work describing a flora and including aids for the identification of the plants it contains such as botanical keys and line drawings that illustrate the characters that distinguish the different plants. Floristics is the study of floras, including the preparation of Floras.
The term flora comes from Latin language Flora, the goddess of flowers in Roman mythology. The corresponding term for animal life is fauna. Flora, fauna and other forms of life such as fungi are collectively referred to as biota.
Plants are grouped into floras based on region, period, special environment, or climate. Regions can be geographically distinct habitats like mountain vs. flatland. Floras can mean plant life of an historic era as in fossil flora. Lastly, floras may be subdivided by special environments:
- Native flora. The native and indigenous flora of an area.
- Agricultural and garden flora. The plants that are deliberately grown by humans.
- Weed flora. Traditionally this classification was applied to plants regarded as undesirable, and studied in efforts to control or eradicate them. Today the designation is less often used as a classification of plant life, since it includes three different types of plants: weedy species, invasive species (that may or may not be weedy), and native and introduced non-weedy species that are agriculturally undesirable. Many native plants previously considered weeds have been shown to be beneficial or even necessary to various ecosystems.
Bacterial organisms are sometimes included in a flora, and sometimes the terms bacterial flora and plant flora are used separately.