Photo of Whorled Milkweed (Asclepias verticillata)
The narrow leaves of whorled whorled milkweed (Asclepias verticillata), with little surface area, make it highly resistant to drought stress, allowing it to quickly colonize dry, sunny sites with soil that is poor at holding moisture. But they come at a tradeoff of making it highly intolerant to shade and competition, and as such, this species is only found as a pioneer of sunny sites.
