prickly lettuce

Lactuca serriola has a spineless reddish stem, containing a milky latex, growing up to 2 metres (6 ft 7 in). The leaves get progressively smaller as they reach its top. They are oblong or lanceolate, often pinnately lobed and (especially for the lower leaves), waxy grey green. Fine spines are present along the veins and leaf edges. The undersides have whitish veins. They emit latex when cut. The flower heads are 1–1.5 cm (1⁄2–1⁄2 in) wide, pale yellow, often tinged purple, with 12–20 ray flowers but no disc flowers. The bracts are also often tinged purple. It flowers from July until September in the northern hemisphere. The achenes are grey, tipped with bristles. The pappus is white with equal length hairs. Lactuca serriola is known as the compass plant because in the sun the upper leaves twist round to hold their margins upright, pointing roughly south or north from the stem. Similar to Mycelis muralis but showing more than 5 florets.

Lactuca serriola is native to Europe, Asia, and North Africa, and has become naturalized elsewhere.

Lactuca serriola can be eaten as a salad, although it has something of a bitter taste. Young leaves can be eaten raw or cooked. Older leaves can be steamed. While unsubstantial, its roots have been used as a coffee substitute. Its presence in some ancient deposits has been linked more to its soporific properties which might suggest ritual use. The Ancient Greeks also believed its pungent juice to be a remedy against eye ulcers and Pythagoreans called the lettuce eunuch because it caused urination and relaxed sexual desire. Following its accidental introduction to North America, the Navajo began to use the plant as a ceremonial emetic. In the island of Crete in Greece the leaves and the tender shoots of a variety called maroula (μαρούλα) or agriomaroulo (αγριομάρουλο) are eaten boiled. It is used by a growing number of Jews and Samaritans as the Maror (bitter herb) on Passover (or Pesach in Hebrew). Lactuca serriola contains lactucarium, which is the milky sap (white latex) that flows through the stem of the plant. It is used as a medicinal herb when air-dried. Although the standard definition of lactucarium requires its production from Lactuca virosa, it was recognized that smaller quantities of lactucarium could be produced in a similar way from Lactuca sativa and Lactuca canadensis var. …

The Egyptian god Min is associated with this species of lettuce. Also, archaeobotanical evidence in Greek archaeological contexts is scanty, although uncarbonised seeds have been retrieved from a 7th-century BC deposit in a sanctuary of Hera on Samos. It is also described by Theophrastus. In mythology, Aphrodite is said to have laid Adonis in a lettuce bed, leading to the vegetable's association with food for the dead.