Take gentians, for example: There is a splendid autumn-flowering one called Gentiana sino-ornata `Angel's Wings.' Here is how its name carves up (according to the international system for plant naming). 1.``Gentiana'' is the genus (plural: genera) of this plant. The genus is like the surname of a plant - but unlike humans, it comes first.
2.The next part, ``sino-ornata,'' is the species. It starts with a small letter, and always comes second. It describes what is different about this particular gentian. The species is a smaller, less-inclusive category than the genus.
3.```Angel's Wings''' is the cultivar name of this plant. This always comes third. It should not be in Latin like the first two names. It should be in single quotation marks, and should begin with capital letters. A cultivar is a plant that has been bred or is cultivated in gardens. So it is unlike genus and species, which are botanical names for plants in nature.
Sometimes other descriptors are added onto a plant's name. When two species are crossed, the result is a ``primary hybrid.'' This can happen in nature, but more frequently it is brought about by gardeners. When a noticeably different individual plant belonging to a species is found - in a meadow for instance - then it might be called a ``variety'' or a ``form.'' (``Form'' denotes a smaller deviation within a given species than a ``variety.'')
Gardening books and catalogs occasionally indicate the botanical ``family name'' of a plant as well. It is the largest category of all. Gentians belong to the family Gentianaceae. Dahlias belong to the family Compositae. So do Dendranthema (they used to be called Chrysanthemums - see main story). So do many plants less familiar to gardeners such as Perezia, Pericallis, Leontodon, and Eumorphia. And so, incidentally, does Bellis - which most people call ``daisy.''