I always thought there were two kinds of hybrids, natural hybrids, which arise spontaneously, and artificial hybrids, which are pollinated by man. But there are certain hybrids that arise spontaneously when an alien species is planted by man near a native one. One well-known example is the Dunkeld larch, Larix xmarschlinsii. Some Japanese larches, Larix kaempferi, were planted on the grounds of a Scottish castle, near the native larch, Larix decidua. Nobody monkeyed with them, but after a while it was noticed that a population of hybrid seedlings abounded in the place. Rafael Govaerts, the editor of the Kew Checklist, refuses to call them natural hybrids. On the other hand, since they arose spontaneously, I don't think they should be called artificial hybrids. Does anybody have information on what they are supposed to be called?
Iris