Other butterfly-friendly plants you can add include blue giant hyssop, wild hydrangea, sweet pepperbush and butterfly milkweed.
From the delawareonline.com
There are popular purples such as A. foeniculum and A. rugosa, the latter bearing the curious common name of wrinkled giant hyssop.
From the sfgate.com
Anise hyssop has acquired a variety of common names, including elk mint, giant hyssop, licorice mint, lavender hyssop, giant blue hyssop and Korean mint.