Helictotrichon sempervirens, the blue oat grass, is a species of flowering plant in the true grass family, Poaceae, native to central and southwest European grasslands.

It is a bunchgrass often used as an ornamental grass in garden design and landscaping.

[2] The grass blooms with pale blue-green flowers in May to August.

The plant is an evergreen perennial, although with summer drought stress semi-dormancy occurs.

[3] This plant has gained the Royal Horticultural Society's Award of Garden Merit.