A new name for the Leyland cypress
December 18, 2008
If there’s one thing gardeners hate more than anything else, it’s plants changing their names. Of course, it’s not the plants’ fault – in fact, basically, the fault lies with our old friend Carl Linnaeus who invented our system of names for living organisms. The problem is that the names are tied so closely to the classification of plants that when a plant is reclassified for some perfectly good reason its name has to change.
Fortunately, it all happens far less than it used to – but now I have to tell you about a name change that has crept up on us in recent years but is now pretty much universally agreed. The botanical name for Leyland’s cypress has changed. It’s interesting to learn why.
For many years the botanical name of the Leyland cypress has been xCupressocyparis leylandii. It’s a hybrid between the Monterey cypress from southern California (Cupressus macrocarpa) and the Alaska cedar (Chamaecyparis nootkatensis) which grows from northern California to Alaska. The generic name is derived from the names of the two parents’ names with a small x in front to indicate that it’s a hybrid. OK, it’s a cumbersome name, but we’ve got used to it. The leylandii part comes from the Leyland estate in Wales where this hybrid first arose.
Now, what might seem like a diversion. In 1999 a new species of conifer was discovered in Vietnam. It was recognised as sufficiently different from other conifers to be given a its own genus and is known as Xanthocyparis vietnamensis. Now comes trouble…
The conifer expert at the Royal Botanic Gardens at Kew, London, recognised that the Alaska cedar (Chamaecyparis nootkanensis) was actually much more similar to the newly discovered Vietnamese conifer than to the other species with which it has been grouped as a Chamaecyparis. The result is that Chamaecyparis nootkanensis was reclassified, moved into the genus Xanthocyparis, and became Xanthocyparis nootkanensis.
And… because the name of one of the parents has changed, the name of the hybrid has to change as well. So the new botanical name of the Leyland cypress is xCuprocyparis leylandii. It's taken a few years for botanists around the world to accept this change, but there now seems to be universal agreement that it makes sense.
And you still shouldn't plant it as a hedge.
You can find the full story on the Royal Horticultural Society website.
At least the change is not as dramatic as the chopping up of American asters into Eurybia, Symphiotrichum and the rest.