Calamagrostis arundinacea var. brachytricha is a fall-blooming perennial, with smoky-purple blooms appearing at the end of summer. Water during dry spells for best appearance. The botanical name Calamagrostis comes from the Greek words kalamos (reed) and agrostis (grass). These clumping grasses are non-invasive with strong vertical habits and tall, slender flower plumes.