Who was this guy, and what did he do to upset everyone?
Most people realise that the same name may pop up for several plants or that one plant may have several names. Common names, useful and convenient where two levelheaded people are in a room with a plant, pointing at it and using a name which identifies it absolutely for them, gradually become less useful as you depart from this situation, and may reach the acme of futility when submitted as a plant identification to a website with readership around the world.
Many common names refer to a plant's form or appearance - elephant's foot, string-of-pearls, gout plant or gray ghost - or to some real or imagined property - heart's-ease, ladies' bedstraw, horseradish tree. They may infer a place of origin (and how often they are wrong!) - English ivy, Rangoon creeper, French mulberry (all the way from Southeastern US to your backyard), and, very commonly, will pick on a character familiar to a group and tack on a modifier, so the 'something apple' is the common name of more than 20 plants in 11 families that all share the character of having an edible fruit, and 'something plum' is almost as widely used.
There are rules that govern the exact written form of this last type of common name, but no rule to say that a plant has its unique common name, or that a name applies to only one plant. We may be promulgating a nonsense name, but by God we taxonomists are going to be grammatically correct.
The origin of some common names is intriguing, and may give an insight into the manners and customs of times long past: scouring rush for Equisetum is an obvious reference to the use of this silica-rich plant for cleaning pots, and the thatch palms (many types with broad leaves) has an equally clear tie-in with roofing for huts in the tropics.
Then there are the names that commemorate some person, some famous and some who may have slipped away from the history books entirely apart from their tie to a plant in some corner of the world. A rank-growing potherb in the genus Chenopodium, with the common name good King Henry, seems to have been given its scientific epithet, bonus-henricus, as a translation of the common name rather than the other way round. It is a long-established name in parts of England, but not really certain which of the monarchs it honors. Lady Doorly lives on in the common name of Ipomoea horsfalliae, but not in any of my reference books as a known character of history. The name is commonly used in the West Indies making me wonder if she graced some island with a fine house and its gardens.
But what got me into this was Creeping Charlie. The name gets used for any unpleasant low weed, as well as for a few basket plants. I have come across it for the following, and I would bet that my list is not complete:
also known as Creeping Jenny. moneywort
So who was this Charlie that everyone recognises as a low and often despicable character? Does the alternative name involving money for some of the plants suggest that his sin was greed? We live in an age of rehabilitation and social reform. If we only knew who he was and what he had done, we could surely find it in our hearts to forgive him.
That same forgiveness can never apply to some of the plants, of course: Glechoma hederacea, as pretty as it may be, would be damned by most gardeners whatever sweet name we might find for it.
Let me know of the other creeping charlies out there, or share whatever is on your mind. firstname.lastname@example.org leads straight to my padded cell.