We all dislike the way the Latin names of plants change. Is it just the whim of the botanists? Are they changing them just for the sake of it, or perhaps to make names for themselves? Or are there sound and necessary scientific reasons for it?
Usually, it is advances in botanical knowledge that lead to changes. Detailed studies of the structure of plants may lead to a decision that previously separated species or genera or families should be united, or that they should be split into several distinct entities. In the past such decisions would be based on morphological characteristics (what the plants look like), but increasingly analysis of the DNA (the chemistry of the plants) is used.
As a recent example, DNA analysis of plants in the genus Dodecatheon has backed up earlier opinions based on their appearance that they really belong in Primula. As they all come from North America, it is not surprising that their closest relatives are American primulas. But that does not mean that North American plant lovers are happy. And particularly not the members of the North American Rock Garden Society, who have the 'shooting star' as their symbol. Of course, the shooting star will still be a valid English language name, so perhaps all will be well. Click here to read about the new names.
Another recent merger (or lumping - the term used by botanists) placed Ledum in Rhododendron, but the reverse process (splitting) also occurs. So the lovely Alaskan Rhododendron camtschaticum was deemed to belong to a distinct genus, and so became Therorhodion camtschaticum. Even a primula was given the push, and Primula grandis now has a genus all of its own, the mouthful Sredinskya.
Those were odd species being separated out, but whole genera are sometimes divided up. Recently the snowflakes, Leucojum, were given this treatment, some retaining this genus name, and the others making up the new genus Acis. And in the same way, families can be merged or, more often, split. The giant Liliaceae family was given this treatment, and there are now a host of smaller and more manageable families. So we now have Hyacinthaceae, which includes not just hyacinths, but also bluebells (the English type) and grape hyacinths; Trilliaceae, which takes in Paris as well as Trillium; Alliaceae, with onions and their like; while dog's-tooth violets (Erythronium), lilies and fritillaries remain in Liliaceae.
Although there are strict rules about how plants are named, whether or not name changes are accepted is much more dependent on public opinion. So although Russian scientists have accepted that a group of irises should now be known as Juno instead of Iris, most of the rest of the world have not. So the whole purpose of having the rules is negated! International consistency does not exist.
Finally, we should note that some name changes have been forced, not by detailed study of plants, but by detailed study of the rules. Insisting that family names must end ...aceae resulted in changes that we have noted in the section on families. So Compositae are now Asteraceae, Cruciferae have become Brassicaceae, Umbelliferae are Apiaceae and Labiatae are Lamiaceae.
