Allium caeruleum

Allium caeruleum is an ornamental bulbous plant of the onion genus, native to Central Asia. In these regions, it is found on dry slopes, plains, and steppes.
This plant is cited in the Flore des Serres et des Jardins de l'Europe puis L'illustration horticole by Charles Antoine Lemaire. It grows to 80 cm, producing strap-shaped leaves and small globes of blue flowers in early summer. The one-inch wide globular flower heads attract butterflies. The plant has been granted the British Royal Horticultural Society's Award of Garden Merit.
A. caeruleum thrives in well-drained soil in full to partial sun. It is deer-resistant and suitable for USDA hardiness zones 4–8.