Does anybody here have an idea of an average lifespan, specifically, Asclepias asperula. I have a few in my yard and I collected seeds. I couldn't find the answer on the internet, maybe I didn't look hard enough. I found one answer to that question, "It's a perennial." It looked like a dodge to me, they didn't know. I know it's a perennial, I want to know how long the plant may live, roots and all until the whole thing gives up the ghost. I think it's an interesting plant and I want to see more caterpillars so I'm going to grow several if it works out.