Aristida purpurea, commonly known as Purple Threeawn or Blue Threeawn, is a perennial grass native to a variety of habitats including deserts, grasslands, open woodlands, and scrub areas in the Southwestern USA, Northern Mexico, and the Central USA. It typically grows to a height and width of 1-2 feet (0.3-0.6 meters), forming clumps of narrow, blue-green leaves. The plant is known for its distinctive purplish inflorescences, which appear in late spring to summer and can add a delicate texture to the landscape. The flowers are not particularly showy, but the seed heads are notable for their three long awns that catch the light and move with the wind.

Purple Threeawn is valued for its drought tolerance and ability to thrive in poor soils, making it a suitable choice for xeriscaping and naturalized areas. It is often used in restoration projects, as it can help stabilize soils and support local ecosystems. This grass prefers full sun and requires minimal water once established, making it easy to maintain. It is also used ornamentally in rock gardens, borders, and as a ground cover. While generally disease-free, it can self-seed prolifically, which may be considered undesirable in some garden settings.CC BY-SA 4.0