Prickly Lettuce - Lactuca serriola

Tall, greyish, stiff and erect plant to 1.8 metres. Stem sometimes bristly. Leaves alternate, oblong, prickly on margins and along the mid-rib beneath, sometimes irregularly lobed, clasping the stem with arrow shaped points. Leaf mid-ribs usually whitish. Upper leaves held in a vertical position, their edges pointing north-south when in sunlight. Flowerheads pale yellow 11 to 13 mm numerous, in a narrow pyramidal panicle. Achenes greyish.

Great Lettuce Lactuca virosa has maroon mid-ribs and stem.

Leaf midrib underside prickly; achenes green-greyish; stems and leaf midribs greenish white.  Leaves variable - usually unlobed, but can be deeply pinnately lobed.

A clear image (or several) showing leaves and stem is usually sufficient. Ideally a close-up of the seeds if available

Disturbed and waste ground, roadside verges, motorway banks.

July to September.

Annual or biennial.

Most records in Britain are from central and southern England.

Once infrequent, but now quite common in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 25 of the 617 tetrads.