Prickly lettuce
Lactuca serriola
Family · Asteraceae · Irritating
The wild ancestor of the garden lettuce, tall and stiff on summer road verges. It has a trick almost nobody knows: in full sun the leaves turn edge-on and all align in the north-south plane.
Roadsides and waste ground · Town and roadside · Fields and pasture
Also known ascompass plant, wild lettuce
How to tell it
A row of soft prickles along the midrib on the leaf's underside, felt by running a finger. Leaves clasping the stem with two pointed ears and held vertically. Abundant white latex. Many small yellow heads.
What it is confused with
Sow thistle
Sonchus oleraceus
Both with white latex and yellow flowers. Run a finger along the underside of the midrib: prickly lettuce has a row of prickles, sowthistle has none. Both edible cooked.
Open sheet →What it is for
Very young leaves eaten cooked, bitter. The dried latex was used as a sedative in 19th-century medicine, under the name lactucarium, a historical use and not a recommendation. The leaf orientation really did serve as an improvised compass in open country.
Traditionally used as food. This is not permission to eat it.
With documented traditional uses. Not a therapeutic indication and not a dose.