The Genus Pages, each of which has a link below, provide basic information about the individual genera, as well as thumbnail images for all of the photos of the particular genus. In some cases substantive articles on the genus or the larger group to which the genus belongs are available on the site, and the the Genus Pages will contain links to those articles. The Genus Pages provide one of the best ways of navigating this site.
The “Genus” is one of the fundamental building blocks in our understanding of how plants are related to one another. In botany, as well as in zoology, species are grouped on the basis of observed similarities. These observations may be limited to the form of the plants (what we call their “morphology”) or on detailed scientific examination of their genetics. Given enough information, inferences can be made with some confidence on the relatedness of plants, and on their evolutionary history. Botanists can identify groups that share a relatively recent common ancestor. Each of these groups of species are referred to as a “genus” — the plural is properly “genera”.
There is often significant disagreement about the proper classification for individual species. Some botanists may be of the opinion that a variant of a species should be classified as a completely separate species; in other circumstances, some may believe that species which have been accepted by others as all belonging to one genus should really be assigned to other genera. There are even sometimes disputes over whether a species properly belongs to one family or another.
It is important to recognize that these “conflicts” reflect the many shades of gray that exist in nature. Human attempts at classification of the natural order will necessarily be at least partially subjective, and hence subject to legitimate differences of opinion.