Fuller's Teasel (Dipsacus fullonum) is a prickly biennial with a basal rosette of simple, oblong-lance shaped, toothed, dark green leaves, 12" or more long, covered in spiny pustules. Paired lance shaped leaves are born on upright stems in the second summer, joined at their bases to form a cup.
Warning: Fuller's Teasel (Dipsacus fullonum) is listed as a Noxious weed in Colorado, Iowa, Missouri and New Mexico. Check your states listing to see if there may be a problem growing this plant.
Source: Various resources including The American Horticultural Society A to Z Encyclopedia of Garden Plants and the USDA