Allium triquetrum, commonly known as three-cornered leek, angled onion, or onion weed, is a perennial herb native to the Mediterranean basin, including southwestern Europe, northwestern Africa, Madeira, and the Canary Islands. It typically thrives in a variety of habitats such as meadows, woodland clearings, river banks, and roadside verges, often up to 2789 feet in elevation. This plant is characterized by its triangular-stemmed leaves and white, bell-shaped flowers with a green stripe that bloom in spring, creating an attractive display. The flowers are followed by capsule fruits containing black seeds.

Three-cornered leek is appreciated for its ornamental flowers and as a culinary herb, with a mild garlic-onion flavor. It is suitable for naturalizing in informal areas of the garden, and can be used in border plantings or as ground cover. It prefers moist, well-drained soils and can tolerate partial shade to full sun. However, it can spread rapidly and become invasive, especially in mild climates similar to its native range. In cultivation, it requires minimal maintenance but should be monitored to prevent unwanted spread.CC BY-SA 4.0