It is both an inventory of the species of plants of a particular group in a definite area, and a means of identifying and naming these plants. Floras usually provide keys to aid identification, as well as descriptions and often illustrations. It is in the last two of these, and particularly the last, that a Flora makes its greatest contribution to botanical knowledge. In New Zealand, Landcare Research is doing ongoing plant biosystematics research that will result in new and updated flora of New Zealand. Floras are basic reference works about the plant world around us.
Floras provide a recommendation as to the correct names of plants in a region.
They are used extensively, both within the region for which they are written and other regions, particularly those which share many of the plants, by both professional and amateur biologists. Floras take many years of careful work and serve as the authoritative text on the plant group within a region. It is often several decades before they are revised in whole or in part. Floras encourage botanical research by highlighting problem groups of plants, and in doing so may soon be out of date. Thus, in New Zealand, where many plant groups are not well understood, there is a need for frequent revision of Floras .