Pokeweed 20 Foxglove 22 Mullein 24 Lobelia 26 Tansy 27 Gum plant 28 Scaly grindelia 29 Boneset 30 Catnip 31 Hoarhound 32 Blessed thistle 34 Yarrow 35 Canada fleabane 36 Jimson weed 37 Purple thorn-apple 39 Poison hemlock 39 American wormseed 41 Black mustard 42 White mustard 44 ILLUSTRATIONS. Page. Fig. 1. Burdock, flowering plant 11 2. Burdock, first year’s growth 12 3. Dandelion 13 4. Dandelion root 14 5. Yellow dock, first year’s growth 15 6. Broad-leaved dock, first year’s growth 16 7. Leaf, fruiting spike, and root of broad-leaved dock 17 8. Yellow dock root 18 9. Couch grass 19 10. Pokeweed 21 11. Pokeweed, flowering and fruiting branch 22 12. Pokeroot 22 13. Foxglove 23 14. Mullein 25 15. Lobelia 26 16. Tansy 28 17. Gum plant 28 18. Scaly grindelia 29 19. Boneset 30