About Lactuca virosa L.
Lactuca virosa L. is a biennial plant that resembles prickly lettuce (Lactuca serriola), but grows taller, reaching up to 200 cm (almost 7 feet/80 inches). It is also stouter than Lactuca serriola, with more purple-tinged stems and leaves. Its leaves are less divided than those of Lactuca serriola, but grow in a more spreading pattern. It resembles Mycelis muralis, but produces more than 5 florets per flower head. Its achenes are purple-black and lack bristles at the tip, and its pappus is identical to that of Lactuca serriola. In the northern hemisphere, it flowers from July to September. For distribution, it occurs along coastal areas of Great Britain, and is rarely found in north-east Ireland. It is widespread across much of central and southern Europe, and can be found locally in south-east and eastern England. It is very rare throughout the rest of Great Britain, and entirely absent from Ireland outside of rare north-east occurrences. It also grows wild in the Punjab region of Pakistan and India, and in Australia. In North America, it is an introduced species that has been documented in California, Alabama, Iowa, and Washington, DC, and grows wild in other parts of the continent.
