A harvestman, or brown daddy-long-legs (that's the common name!), appreciating my butterflyweed with me. Since they feed on small insects and decaying organic matter, I'm guessing this one is lying in wait for prey, and not about to eat my plant.
These guys also congregate in my kayak, and emerge whilst I'm out on the water, tickling me lightly and annoyingly, I might add, as they crawl all over me. They're harmless, but the irritation of them on my skin makes me want to shoo them away. Problem is, they're quite delicate, and I try not to kill them when I brush them off, so they're soon back!