Donkey-tail spurge or myrtle spurge is a study in perspectives. From a gardening point of view, you see a structurally-interesting plant that is drought-tolerant and ignores poor soils. In fact, the Royal Horticultural Society has given this species its Award of Garden Merit.
The relative ease in which it grows and propagates itself in a garden setting, however, is a red flag for qualities associated with a potential invasive under the right conditions, and thus a plant of concern to ecologists and conservation biologists. It has indeed displayed invasiveness; it is listed as a “noxious weed” in the states of Washington, Oregon and Colorado (source: USDA Plants Database). However, the invasiveness potential seems to be restricted to the western USA. The distribution map shown as part of the Plants Database marks no plants in the wild in Missouri, even though it seems to be a popular garden plant in that state.
Photography resource link: For inspiration, the photography of Eric Fredine. Prairie water landscapes, something I consider a “fresh” subject for photography. One challenge of many photographs is to not take pictures of the “same old, same old”. Eric's accomplished that.