Many poppy species produce a rosette of jagged leaves resembling lettuce that encircles their flower stalks. The ladybird poppy (Papaver commutatum) produces blue-green, fringed leaves. The Iceland poppy (P. nudicaule) similarly grows a rosette of jagged-edge leaves, resembling arugula. The brilliantly colored flowers of these species grow on stalks forming the center of their leaf arrangements.
Various lettucelike weeds grow on roadsides or on lawns. Prickly lettuce (Lactuca serriola) has elongated leaves similar to some commercial lettuces. It is a member of the daisy family and produces flowering stems surrounded by a rosette of green leaves, which are edible and taste like lettuce. It grows in rough environments, such as near railroad tracks, alleys and sidewalks, but grows best in nutrient-rich soil. Dandelions are a group of wild-growing edible greens with jagged, lettucelike leaves growing around stalks with yellow flowers.
The Drumstick primrose (Primula denticulata) produces dense clusters of violet, red, pink or white flowers on long stalks. It grows widely around the world in flower gardens, but produces rosettes of lettucelike leaves after flowering. Like most types of lettuce, the foliage is sensitive to heat and drying. It wilts under these conditions and needs plenty of moisture to thrive.
All edible lettuce types transition to a reproductive part of their lifecycle when temperatures rise, or after a few months of growth. This stage is called bolting. The edible leaves of the lettuce head diminish in size and turn bitter, and energy is redirected into producing a large, flower stalk. Flower stalks may reach 1 or more feet tall, depending on variety, and can produce showy, colorful flowers.