Lactuca serriola

Common Names: Prickly Lettuce, Milk Thistle, Compass Plant, Scarole
Synonyms:
Family: Asteraceae (Sunflower)
Genus Information: 50 to 75 species

Prickly Lettuce

It has a slightly fetid odor and is commonly considered a weed of orchards, roadsides and field crops. It is the closest wild relative of cultivated lettuce (Lactuca sativa). It is native to Eurasia and north Africa, and has become naturalized elsewhere. 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 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 native to the Mediterranean region and occurs along roadsides, in abandoned fields, and other disturbed areas. It was accidentally introduced into North America in the late 1890s, possibly as a contaminant in seed. 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. It can be eaten as a salad, although it has something of a bitter taste. Young leaves can be eaten raw or cooked.