Plant Societies Botanical Gardens Hort. I'll try to help you. For additional info, there's my Cyber Sites for Herbs - if you find one that doesn't connect, please email me. A native wild perennial plant which is found in moisture retentive soil in shady to partially shady sites.
Propagation is by seed and there are a number of ornamental cultivars for the home garden.
Flowers appear in July. The above ground portion of the plant while in flower to be dried and used in infusions. The spent flower stalks are also collected in autumn to be dried and used in decoctions. It can be invasive so deserves its own growing area. It requires full sun and a good garden soil.