Prickly Lettuce
Lactuca serriola

Family: Sunflower (Asteraceae)
AKA: Compass Plant, Milk Thistle
Photo taken on: July 27, 2009
Location: White Rock, NM
Life Zones: Plains
Habitat: Dry areas, roadsides, fields

Grows to 4ft tall with a much-branched stem. Flowers are small and numerous. Leaves have spines along the mid-rib and on the edges. In the sun the leaves twist so that edges are upmost.

Flora of North America reference.