Monographs Details: Lactuca
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Genus Description - Fls all ligulate and perfect, yellow, blue, or white, the cor- tube generally more than half as long as the ligule; invol cylindric, often broadened at the base in fr, generally imbricate, occasionally merely calyculate; achenes compressed, winged or strongly nerved marginally, with 1 or several lesser nerves in each face, beaked or sometimes beakless, but in any case expanded at the summit where the pappus is attached; pappus of 2 rows of usually equal capillary bristles, none markedly coarser than the others; lactiferous herbs with alternate, entire to pinnatifid lvs and usually numerous heads with relatively few fls (5–56 per head in our spp.), the infl mostly paniculiform. (Mulgedium, Mycelis) 50, Eurasia, Afr., and N. Amer.