264 A GUIDE TO THE WILD FLOWERS 



most of our species are herbs, many in the tropics are shrubs 



and trees. There is one vine in this region, ^ee No. 199. All 



the rest may be divided thus: 



Heads exclusively of ray flowers; plants with milky juice no. 908 



Heads of tubular flowers, or with tubular and ray flowers, never 



exclusively of ray flowers; plants without milky juice (except 



in the Pilewort, no. 840) 



Flower heads with both tubular and ray flowers, (except in 



Beggar Ticks, no. 900) no. 847 



Flower heads exclusively of tubular flowers 



Leaves alternate or basal no. 819 



Leaves opposite, or in clusters 

 Flowers white 



Leaves in clusters of 6-10 Thoroughwort no. 810 



Leaves opposite 



Leaves stalked White Snake-root no. 811 



Leaves stalkless, or nearly so 



Leaves stem-clasping Boneset no. 812 



Leaves not stem-clasping 



Plant 1-3 ft. high ... White Thoroughwort no. 813 

 Plant 3-6 ft. high . . Vervain Thoroughwort no. 814 



Flowers pinkish-purple ; leaves in clusters 



Joe-Pye Weed no. 815 



Flowers green or greenish-yellow 



Salt marsh plant 3-12 ft. high Marsh Elder no. 816 



Plants of waste places and fields 

 Plant 1-2 ft. high; leaves not lobed . . Galinsoga no. 817 



Plant 3-10 ft. high ; leaves lobed or divided 



Ragweed no. 818 



810. Thoroughwort. Enpatorium hyssopifolium. A rough- 

 hairy, densely branched perennial, 1-2 ft. high. Leaves nar- 

 row, linear, }i-iy^ in. long, mostly in clusters. Flowers 

 white, tubular, the heads cylindric, about ^ in. long, in pro- 

 fusely branched clusters. In dry sandy places, Mass. to 

 Florida and Texas. August. Fig. 810. 



811. White Snakeroot. Eupatorium urticacfoliuni. A 

 smooth or sometimes sticky perennial, 1-4 ft. high, and 

 usually branched. Leaves opposite, stalked, oval, broad or 

 rounded at the base, narrowed to a point at the tip, 3-5 in. 

 long and sharply toothed. Flowers tubular, white, scarcely 

 y^ in. wide, but in profusely branched clusters. In rich woods. 

 New Brunswick to Florida, and westward. July-November. 

 Fig. 811. 



