valerian
Valeriana officinalis

Hardiness: Zones 4 to 7
Plant type: Herbaceous perennial
Height: 3- 5'
Spread: 2- 4'
Sun: Full sun
Water: Medium to wet
Bloom time: June to July
Bloom color: White to pale pink
Soil: Rich to average garden soil, loams, can tolerate poorer soils.

Notes: It is grown medicinally for the sedative effects of the plant's roots.

More information on this plant here.