Lactuca saligna L.
Family - Asteraceae
Stem - Erect, to 1 m or more, glabrous, sometimes glaucous, light tan; latex white.
Stem and leaves.
Leaves - Well developed along stem, to 15 cm long, narrow, sessile and clasping, auriculate, glabrous or occasionally with short hairs along abaxial midvein.
Inflorescence - Narrow panicles with numerous heads.
Involucre - 7-9 mm long, cylindrical.
Flower - Ligulate florets 11-14, pale yellow, with pappus of 4-6 mm bristles.
Fruits - 3.0-3.5 mm long, flattened, gray or brown, ridged, with beak 1.5-2x length of body.
Flowering - July - October.
Habitat - Forest openings, glade margins, many types of disturbed areas.
Origin - Native to Eurasia
Other info. - Both the leaves and the inflorescence of this plant are quite narrow, and these characters provide relatively easy means of differentiation from other lettuces. "Saligna" means "willow-like," referring to the narrow leaves. This species is less commonly encountered than the other small-flowered, yellow Lactucas (L. serriola and L. canadensis). Some authors have divided this species into multiple infraspecific types based upon leaf shape, but since these forms tend to occur within the same population, the division is questionable.
Photographs taken in Labadie, Franklin County, MO, 8-1-2012 (SRTurner).