tufted hairgrass
Deschampsia cespitosa

Hardiness: Zones 4 to 9
Plant type: Grass
Height: 2- 3'
Spread: 1- 2'
Sun: Part shade
Water: Medium
Bloom time: July to September
Bloom color: Gold, silver, purple, and green tones
Soil: Loamy, average well-draining soils, Neutral (≈7)

Notes: Provides erosion control, offers showy flowers, attractive seedheads and winter Interest. 

More information on this plant here.