Prickly Lettuce - Lactuca serriola

A tall plant that may be up to 2m high but often much shorter.  The stem is leafy and may be branched, and the leaves are often unlobed and sharply toothed, but may also be deeply pinnately-lobed.  The stems and leaf midribs are usually pale greenish-white.  The flowers are small and a light yellow and in panicles. The ripe fruits or achenes olive-grey, with narrow wings and a white beak. 

Great Lettuce Lactuca virosa has achenes that are blackish or maroon when ripe.  It usually has deeply lobed leaves with a maroon tinge and maroon midrib and stems, but this is variable.

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

For a certain identification, we recommend that achenes are examined and photographed.  Also photograph the plant in its habitat showing stem colour and leaf shape, and the leaf undersides. 

Disturbed and waste ground, roadside verges, motorway banks.

July to September.

Annual or biennial.

Common