Zone:  4-6
Height:  60-90cm  [2-3ft]
Spread:  20cm [8in]
Bloom:  May-June; lavender-blue with yellow-gold details in falls 
Foliage:  Lance-shaped, green
Light:  Full sun to part shade
Water:  Moist, seasonally flooded, but also drought tolerant
Soil:  Sandy average (not too rich)
Garden Location:  Mid-border; nice naturalized near water (loves living in ditches and wet spots)