COMPOSITE FAMILr 



COMPOSITAE 



BLUE LETTUCE 



Lactuca floridana (L.) Gaertn. 



^- The Blue Lettuce grows in moist open places or moist woods 

 from New York and Pennsylvania to Nebraska and southwest, 

 blooming from July to September. The stem is rather stout, 



smooth, 3-7 feet high 

 and leafy up to the large 

 inflorescence. Like all 

 species of wild Lettuce, 

 it contains an abundance 

 of milky juice. The 

 leaves are smooth above 

 but somewhat hairy on 

 the veins beneath. 



The numerous heads 

 are borne on scaly pe- 

 duncles, and the flowers, 

 with strap-shaped cor- 

 ollas 5-toothed at the 

 end, are blue. The bracts 

 of the involucre are in 

 several series, the outer 

 much smaller than the 

 inner. The akenes are 

 thick, somewhat flat- 

 tened, and narrowed at 

 the end into a distinct 

 beak which supports the 

 bristly white pappus, well adapted for wind dissemination. 



The Hairy-veined Blue Lettuce, Lactuca villosa Jacq., is 2-6 feet 

 tall and its leaves are 4-6 inches long, sessile and clasping. They 

 have short stiff hairs on the veins beneath, hence the common name. 



The Tall Blue Lettuce, Lactuca spicata (Lam.) Hitchc, is also 

 common in moist soil. The smooth stout stems are 3-12 teet high 

 and are leafy to the inflorescence. The leaves are sometimes entire 

 but are more often variously toothed and lohed. They are mostly 

 sessile but the lower are often narrowed into short-margined petioles. 

 They are 5-12 inches long, 2-6 inches wide, and are smooth on both 

 sides or somewhat hairy on the veins below. The green heads are 

 very numerous, about one-quarter inch broad and tipped with dull 

 purple to whitish rays. The akenes are oblong and narrowed above 

 into a short beak. The pappus is brown. 



390 



