Bulbs 3-4, not clustered on stout, primary rhizomes, ovoid, asymmetric, 2.5-3 × 2-5 cm; outer coats enclosing 1 or more bulbs, light yellow to light brown, thin, papery, chartaceous, cells narrow, vertically elongate, without fibers; inner coats white, cells narrow, vertically elongate. Leaves usually persistent, 3-6, scarcely ensheathing scape even basally, sheaths not extending much above soil surface; blade solid, flat, broadly channeled, 10-60 cm × 10-25 mm, margins entire. Scape usually persistent, solitary, erect, solid, terete, fistulose, 60-100 cm × 5-10 mm. Umbel persistent, erect, compact, 75-150-flowered, hemispheric-globose, bulbils unknown; spathe bracts persistent, 2-4, 11+-veined, ovate, ± equal, apex acuminate. Flowers stellate to subcampanulate, 6-9 mm; tepals ± spreading, white with green midvein, narrowly oblong, ± equal, becoming ± rigid and reflexed in fruiting, margins entire, apex obtuse; stamens included; anthers yellow or purple, aborting without producing pollen; ovary crestless; style linear, ± equaling tepals; stigma capitate, scarcely thickened, obscurely 3-lobed; pedicel 25-40 mm. Seed coat not known.
Flowering Jun. Disturbed roadsides; 100--200 m; introduced; Oreg.; native to Mediterranean; cultivated in Europe.
Native to the Mediterranean and long-cultivated in Europe, Allium nigrum is reported to be well established near Perrydale, Oregon, and may be expected elsewhere in North America. This species is remarkable in its lack of an onion/garlic odor. It is also unusual in having more than two ovules in each locule, a characteristic of sect. Melanocrommyum Webb & Berthelot but otherwise unusual in the genus.