Asclepias tuberosa: flowers

Asclepias tuberosa, known in English as butterfly weed, butterfly milkweed, butterfly flower, pleurisy root or glory flower (the last is an apparent marketing ploy to win over gardeners who won't grow "weeds"), and in French as asclépiade tubéreuse, is a perennial native to eastern North America. Although related to the common milkweed, Asclepias syriaca, butterfly weed lacks milky sap. The leaves are narrower than milkweed, dark and glossy, and the flowers are a vivid orange (there are yellow and red cultivars available). Like milkweed, butterfly weed (indeed, all of the Asclepias species) is a larval host for the monarch butterfly.

I purchased the plant in the photo from Real Canadian Superstore in 2007. It didn't bloom at all the first year I had it, or show much growth at all. I was pleasantly surprised in 2008 when it emerged at least three times as big as the year before and with lovely blooms.