Sand Leek

Allium rotundum is native to central and southern Europe. It is reported as established in southern Michigan, and is to be expected elsewhere in the Great Lakes region.

Bulbs 1–50+, ovoid, 0.2–1.5 × 0.2–1 cm; outer coats surrounding numerous, very dark purple bulbels, usually white or greenish, membranous, sometimes breaking into ± parallel, fibrous strips; inner coats white, cells obscure, quadrate. Leaves persistent, 2–5, sheathing 1/3–1/2 scape; blade solid, flat or channeled, carinate, 15–40 cm × 2–5(–7) mm, margins entire. Scape persistent, solitary, erect, ± solid, 25–90 cm × 1–4 mm. Umbel persistent, erect, very dense, 80–200-flowered, globose, bulbils unknown; spathe bracts caducous, 2, 7–12-veined, lanceolate, ± equal, apex narrowed to beak, beak to 2 cm. Flowers campanulate, 4–7 mm; tepals erect, purple, or inner with broad whitish margins and purple midvein, oblong to ovate, ± equal, becoming keeled and ± rigid in fruit, margins entire, apex acute to obtuse; stamens included; filaments: outer unlobed, inner with 2 prominent teeth on either side of anther, teeth 2–3 times anther-bearing portion, usually papillose to ciliate; anthers yellow or purple; pollen light yellow to white; ovary crestless; style linear, ± equaling anther-bearing portion of stamens; stigma capitate, unlobed; pedicels 5–30 mm, outer much shorter than inner. Seed coat dull; cells each with central papilla.

Flowering May--Jul. Disturbed fields and roadsides; introduced; Mich.; c, s Europe.

Allium rotundum, common name round-headed leek or purple-flowered garlic, is a Eurasian and North African species of wild onion. Its native range extends from Spain and Morocco to Iran and European Russia. It is sparingly naturalized in parts of the United States (Michigan and Iowa). The species grows in disturbed habitats such as roadsides, cultivated fields, etc.

Allium rotundum produces large clumps of as many as 50 egg-shaped bulbs, each up to 1.5 cm long. Leaves are up to 40 cm long. Scapes are up to 90 cm tall. Umbels look round from a distance, and can contain as many as 200 flowers. Flowers are bell-shaped, up to 7 mm across; tepals purple, sometimes with white margins; anthers yellow or purple; pollen yellow or white.