Mistletoe white berries that it bears in clusters of two to six. The Eastern mistletoe of North America is similar, but has shorter, broader leaves and longer clusters of 10 or more berries. The word 'mistletoe' derives from the older form 'mistle' adding the Old English word "tān" (twig). 'Mistle' is common Germanic (Old High German "mistil", Middle High German "mistel", Old English "mistel", Old Norse "mistil"). Further etymology is uncertain, but may be related to the Germanic base for 'mash'. Parasitism has evolved at least 12 times among the vascular plants . Molecular data show the mistletoe habit has evolved
Mistletoe host, it usually is possible to save a valuable branch by pruning and judicious removal of the wood invaded by the haustorium, if the infection is caught early enough. Some species of mistletoe can regenerate if the pruning leaves any of the haustorium alive in the wood. All parts of the Mistletoe plant are toxic, though its effects are not usually fatal. The active substances are Phoratoxin (in "Phoradendron") and Tyramine (in "Viscum") and their effects are blurred vision, diarrhoea, nausea and vomiting. Less commonly they cause cardiac problems; seizures, hypertension, and even cardiac arrest. Toxins are more concentrated in