Prickly Lettuce - Lactuca serriola

Description

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. 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.

Similar Species

Great Lettuce Lactuca virosa

Identification difficulty
ID guidance

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

Recording advice

The County Recorder has asked for a specimen of this plant to be retained for verification.  Photos showing stems, leaf midribs and achenes.  This plant cannot be verified from a photo of the flowers only

Habitat

Disturbed and waste ground, roadside verges, motorway banks.

When to see it

July to September.

Life History

Annual or biennial.

UK Status

Most records in Britain are from central and southern England.

VC55 Status

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.

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map