Tall Blue Lettuce, Wild Blue Lettuce: Lactuca biennis (Synonyms: Lactuca spicata, Lactuca spicata var. integrifolia, Muledium spicatum, Mulgedium spicatum var. integrifolium, Sonchus biennis)
Canada Lettuce, Canadian Wild Lettuce, Florida Blue Lettuce: Lactuca canadensis (Synonyms: Lactuca canadensis var. integrifolia, Lactuca canadensis var. latifolia, Lactuca canadensis var. longifolia, Lactuca canadensis var. obovata, Lactuca canadensis var. typica, Lactuca sagittifolia, Lactuca steelei)
Least Lettuce, Willow Lettuce, Willowleaf Lettuce: Lactuca saligna (Synonym: Lactuca saligna var. runcinata)
Garden Lettuce: Lactuca sativa (Synonyms: Lactuca scariola var. integrata, Lactuca scariola var. integrifolia)
Prickly Lettuce: Lactuca serriola (Synonyms: Lactuca scariola, Lactuca scariola var. integrata, Lactuca scariola var. scariola)