Butterfly-weed (Asclepias tuberosa) taken yesterday morning off of the bike trail near Masontown. Asclepias tuberosa is a species of milkweed native to eastern North America. It is the larval food plant of the Monarch butterfly. I've always looked for those caterpillars on "regular" old milkweed plants. I'll have to give these a closer inspection for caterpillars in the future.