Could be mistaken for : a bolted example of Garden Lettuce but that is shorter at 75cm and neither (slightly) foetid nor prickly, with un-lobed and un-toothed leaves.

Some similarities to : Great Lettuce but that is both taller and stouter, has prickles on the stems, and the stems are tinged purple. Both have prickles on the mid-rib of the underside of the leaf and ooze a milky sap.

Uniquely identifiable characteristics

Distinguishing Feature : Perhaps the spines on the underside of the leaf along the mid-rib. The greyish-green leaves and whitish main stem.

No relation to : Prickly Poppy, Prickly Heath or Prickly Saltwort, [plants with similar names].

The stems and flowers are tacky to touch leaving the fingers sticky. Broken stems ooze a toxic white latex consisting of sesquiterpene lactones, just like the broken stems of Great Lettuce. It is a casual urban weed, preferring to grow between pavings and in the nook between wall and paving where there is no trampling and little competition from other plants. Also in recently disturbed ground.

In strong sunshine the upper leaves twist around to hold their edges upright in a north-south direction in an effort to avoid the worst of the midday sun, a phototropic response, hence the alternative name of Compass Plant. This is unusual in England but can happen during hot years in southern counties such as Sussex. Mainly a southern UK plant, but mostly avoiding Wales apart from near the coastline.

It smells slightly foetid.