Matching Pairs Weed Species #1Online version Weed Species #1 by Hannah Horak 1 Common Mallow 2 Common Sunflower 3 Common Milkweed 4 Buckhorn Plantain 5 Canada Thistle 6 Barnyard Grass 7 Broadleaf Plantain 8 Common Purselane 9 Common Chickweed 10 Common Lambsquarter 11 Black Nightshade 12 Common Cocklebur 13 Bull Thistle 14 Common Ragweed 15 Cheat