|thistle (Cirsium spp.)||
thistle (Cirsium spp.; COMPOSITE FAMILY [Asteraceae]) Mostly coarse, tall biennial or perennial herbs with painfully spiny leaves. Distinctively shaped heads typically cupped with bristly bracts, topped by a purple tuft formed by the protruding long, narrow corolla lobes of the (exclusively) tubular flowers. The biennial species form a rosette of prickly leaves that overwinters the first year. Roughly 12 species in our area, both native and alien. Some alien species are invasive. Found in marshes, prairies, and waste places. Flowers in summer and fall. 
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