bullweed

noun

1. (countable, uncountable)Knapweed.

   “For this reason it is most excellent practice to mow the weeds of Lambsquarter, Ragweed, Hog Ragweed, Bullweed, Artichoke, and in fact all other weeds large enough to sustain such borers – mowing them about the middle of the summer and again the latter part of August.”

   “Along the narrow creekstone roads, the winter landscape is etched in myriad shades of brown — sedge grass and bullweed stalks, barren trees on a carpet of fallen leaves, decaying shells of unpainted houses staring blankly through vacant windows.”

   “Around the tower, the Citadel lay spread out like a peasant's counterpane of blackish grays and maroons and a dozen faded hues of homespun buff, stitched here and there with the dull green of dusty bullweed and cactus.”