About Asphodelus fistulosus L.
Asphodelus fistulosus is a plant species with common names including hollow-stemmed asphodel, onionweed, onion-leafed asphodel, and pink asphodel. It is native to the Mediterranean region, the Arabian Peninsula, Transcaucasus, and Madeira. It is an invasive exotic weed in the United States, with major infestations in California, Arizona, New Mexico, and Texas, and is listed as a Federal Noxious Weed by the United States Department of Agriculture. It is also a common weed in parts of Australia, New Zealand, and Mexico, and it grows well in any area that has a Mediterranean climate.
This plant is an annual or short-lived perennial herb that produces a hollow stem that can grow up to 70 cm (28 inches) tall. Its root system has a set of tuber-like structures at the base of the stem. The plant forms a large tuft of rounded, hollow, onion-like leaves that grow up to 30 cm (12 inches) long. The inflorescence is a panicle with widely spaced flowers. Each flower is 5–12 mm (0.2–0.5 inches) wide, with six tepals that are typically white or very pale pink marked with a distinct, straight central longitudinal stripe in brown to reddish-purple. The flowers open during the day, closing at night and during overcast or low-light weather conditions. The fruit is a rounded capsule that holds six seeds. Two subspecies of Asphodelus fistulosus are currently accepted: Asphodelus fistulosus subsp. fistulosus, which occurs in the Mediterranean basin, Arabian Peninsula, and Transcaucasus, and Asphodelus fistulosus subsp. madeirensis Simon, which occurs in Madeira.
