Lactuca serriola

Common Name: 
prickly lettuce, compass weed, compass plant
Scientific Name: 
Lactuca serriola L., syn, Lactuca scariola
Family Name: 
Asteraceae (Compositae) - Aster or Sunflower Family
Identification Notes
Life Cycle
introduced annual, winter annual or biennial, reproducing by seed
Stems
upright, tall, usually prickly near ground, leafy, hollow
Stems of Prickly Lettuce
Stems of Prickly Lettuce
Stems of Prickly Lettuce
Stems of Prickly Lettuce
Stems of Prickly Lettuce
Stems of Prickly Lettuce
Stems of Prickly Lettuce
Leaves
alternate, oblong to oblanceolate, deeply lobed, lobes tip pointed backwards (sometimes unlobed), usually linear above, margins toothed or prickly, stem leaves clasping with bases pointed, blueish-green, midrib below with yellow prickles
Leaves of Prickly Lettuce
Leaves of Prickly Lettuce
Flowers
heads of yellow ray (ligulate) florets; terminal clusters
Flowers of Prickly Lettuce
Flowers of Prickly Lettuce
Other: 
contains milky sap