Unlike common milkweed, butterfly weed does not spread by runners. Once the cotyledon first round leaves emerge they occasionally have the seed casing attached make sure you allow it to fall of naturally don t pull it off. C Individual anther prior to dehiscence showing an outer epidermis with the beginning of a longitudinal groove stomium arrow.  Source: <a href=http://www.spighisrl.it/butterfly-weed-seeds-butterfly-milkweed-seeds/>http://www.spighisrl.it/butterfly-weed-seeds-butterfly-milkweed-seeds/</a>