River oats
Chasmanthium latifolium

Hardiness: Zones 3 to 8
Plant type: Grass
Height: 2- 5'
Spread: 1- 2.5'
Sun: Full sun to part shade
Water: Medium to wet
Bloom time: August, September
Bloom color: Green, turning purplish brown
Soil: Moist, organically rich soils, loamy, average well-draining soils, Neutral (≈7).

Notes: Winter interest and texture, may need staking.

More information on this plant here.