Helictotrichon sempervirens, or blue oat grass, is a species of flowering plant in the Poaceae family of true grasses, native to central and southwest European grasslands. It is a bunchgrass often used as an ornamental grass in garden design and landscaping. The foliage is pale green with a tinge of blue. It grows in an arching shape, up to 140 cm (55 in) tall by 60 cm (24 in) wide. The grass blooms with pale blue-green flowers in May to August.