091 Lactuca serriola L.
Nome comune: Lattuga selvatica; Scarola; Lattona; Erba bussola
Prickly Lettuce (Lactuca serriola) is an annual or biennial plant, slightly foetid, that is commonly considered a weed of orchards, roadsides and field crops. The closest wild relative of cultivated lettuce (Lactuca sativa L.), it grows throughout the temperate regions of all major continents. The leaves grow along a spiny stem and get progressively smaller as they reach its top. They emit a milky sap when cut. Many flowers are produced and usually appear in the upper part of the plant.
It is also known as the compass plant, as in the sun the upper leaves twist round to hold their margins upright. 
It is found in southern Britain and fairly common in the rest of Europe.
It has a hairless reddish stem, containing a milky latex, growing from 30 to 200cm.
The leaves are oblong lanceolate, often pinnated (especially for the lower leaves), waxy grey green. Fine spines are along the edges. The undersides have whitish veins.
The flower heads are 11 to 13mm wide, are pale yellow, often tinged purple. The bracts are also often tinged purple. It flowers from July until September.
The achenes are grey, bristly tipped. The pappus is white with equal lengthed hairs.
The plant can be eaten as a salad, although it has something of a bitter taste. However, 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. The Navajo used the plant as a ceremonial emetic. In the island of Crete in Greece the leaves and the tender shoots of a variety called maroula (µa????a) or agriomaroulo (a????µ??????) are eaten boiled by the locals.
The Egyptian god Min is associated with this variety 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.