Sisymbrium irio L.

Lodon Rocket

Herb

Annual

Vascular

London Rocket is an introduced annual in the Mustard family (Brassicaceae). It is native to Europe, western and central Asia, and North Africa. In the United States it is widely distributed in the northeast and west. In Alabama, it is known from a single county where it was found as a weed in cracks along a sidewalk. London Rocket is an annual from a tap root. Glabrous or slightly pubescent stems are branched near the base and up to 3 feet in height. Basal leaves are petiolate, oblanceolate to oblong in outline, with lobed or dentate margins. Stem leaves are smaller, sessile, and less lobed to entire. Flowers are produced in racemes at the apex of the stems. The racemes become greatly elongated in fruit. Flowers have 4 yellow petals. The fruit is an elongate silique (a dry fruit that is more than three times as long as wide, and that splits at maturity with the seed exposed on a papery septum). The common name of this species is said to have originated after the Great London Fire of 1666 when the species was very common in the burned areas of the city. In portions of the western United States London Rocket is a serious winter weed in fields and pastures.--A. Diamond

This species was first collected in Alabama by A. Diamond in 2010.

Not Native

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