A few weeks ago, David and I tramped around Greenspring Gardens, and I found the plant below, which I described as a nice-looking weed in a previous post.
A nice weed, Greenspring Park Fall 2014
I have discovered more information.
Although considered an invasive weed in some locales, the plant is one of the Asclepias beloved by Butterflies. It also make a nice cut flower.
from the National Botanical Garden
Monarch Butterfly Caterpillars
Asclepias Physocarpa: Gomphocarpus physocarpus, Goose plant, Giant swan milkweed, Hairy balls, Family jewels, Oscar, Cotton-bush, Balloon plant;
Probably a native of southeast Africa, Gomphocarpus is a wonderful butterfly plant. Its clusters of white flowers are insignificant but the light green balloon-like seed pods make it a great plant for a border. The pods pop open like our native milkweed spilling thousands of airborne seeds.
Gomphocarpus can be an aggressive self seeder in some locales, and some of them are poisonous, so care should be taken. It is most commonly sold as Asclepias physocarpus.
I am linking this post to the Nature notes meme (link in my blogroll).