Lactuca species - Lettuce

Lactuca serriola- Prickly Lettuce Tall (2m), increasingly common street weed with small capitulum on spreading branches.

In the sun the leaves are held near vertically in a north-south orientation.

Leaves can be entire or pinnately lobed and have a pale white midrib with a flat edge and underneath are sharply toothed. When bruised smells of lettuce.

Achenes flattened and with a beak as long as the achene, light brown in colour with many simple bristles at the apex.

The are two forms of this plant:

- Lactuca serriola f. integrifolia with entire leaves, and;

- Lactuca serriola f. serriola with pinnatifid leaves.

Both occur in the vice-county.

Lactuca virosa - Giant Lettuce is similar but can have a red-tinged stem. The leaves tend to have undulate margins and larger dark brown / black achenes often with a few palmate bristles at the apex..

Lactuca sativa Garden Lettuce Has entire middle stem leaves which are broader to orbicular, sessile and can clasp the stem and are not held vertically. There are no spines below. The flowers are yellow, often streaked violet and the achene are nbeaked and pale or white.