Why the butterfly bush or summer lilac (Buddleja davidii) is neither a butterfly plant nor a true lilac.
The fact that the flowers of the so-called butterfly bush are regularly visited by butterflies doesn’t make this shrub, originally native to Tibet and China, a butterfly plant.
It has little to nothing to offer most caterpillars of European and North American butterflies. Where Buddleja davidii occurs invasively, it can even displace their native host plants.
And unfortunately, it has a tendency to become invasive.
For many butterflies, by the way, the caterpillar stage lasts longer than the life of the adult butterfly. Caterpillars also have a significantly higher food requirement than adult butterflies.
On top of that, some butterflies are specialized on very specific plants. Their caterpillars cannot survive without them. They can’t simply switch to a new host plant at short notice.
The butterfly bush, also called summer lilac, is a good example of how misleading common names can sometimes be.
Buddleja davidii is neither a true lilac nor a butterfly plant in the ecological sense. It does not belong to the olive family like lilacs (Syringa), but to the figwort family (Scrophulariaceae).
It is related to plants such as figworts (Scrophularia). Several native species of this genus occur in North America, and some of them are important food plants for butterfly caterpillars. It is also related to the native European mulleins.
What the so-called summer lilac and the true lilac do have in common is that both have escaped cultivation and established themselves outside their native range.
But Buddleja davidii is by far the more aggressive spreader of the two and is officially listed as a noxious weed in several US states.
Categories: Shrubs & Trees |
