KEY FOR JUNE TO NOVEMBER 



Terrestrial Green Herbs With Distinctly Yellow Flowers 



260 a Flowers yellow, not at all red or merely with a yellow 



center 261 



b Flowers not yellow 392 



261 a Numerous small flowers collected into a dense head 



which is subtended by an involucre of green bracts. . 262 

 b Flowers not arranged completely as in a 293 



262 a When open each flower in the head with a strap-shaped 



corolla, as in the Dandelion Chicoriaceae. p 218 



b None or only the outer row of flowers in the head with 



strap-shaped corollas 263 



263 a None of the flowers in the head with strap-shaped 



corollas 264 



b The outer flowers in the head with strap-shaped corollas 273 



264 a Herbs with spiny-toothed leaves 265 



b Herbs not with spiny-toothed leaves 266 



265 a Outer bracts of the involucre with pinnately-branched 



spines Cnicus. p 240 



b Outer bracts of the involucre with unbranched spines 



Carduus. p 239 



266 a Some or all of the leaves pinnately divided or dissected 267 

 b None of the leaves pinnately divided or dissected .... 271 



267 a Leaves compound with leaflets 1-6 in. long, ovate to 



lanceolate; pappus of barbed awns Bidens. P 236 



b Plants not completely as in a 268 



268 a Only the lower leaves pinnately divided. .. .Polymnia. p 234. 

 b All of the leaves more or less pinnately divided 269 



269 a Heads erect or drooping, not arranged in corymbs 



Artemisia, p 238 



b Heads erect, arranged in corymbs 270 



270 a Plants aromatic Tanacetum. p 237 



b Plants not aromatic Senecio. p 238 



271 a All of the leaves with entire margins Gifola. p 2 3 3 



b Some or all of the leaves with toothed or incised margins 272 



272 a Achenes crowned by a pappus of 2-4 stiff, barbed awns 



Bidens. p 236 

 b Achenes not crowned by a pappus Polymnia. p 234 



273 a Leaves wanting at flowering time; flowering stalk with 



alternate, woolly bracts Tussilago. p 238 



b Leaves present at flowering time 274 



274 a Some or all of leaves opposite 275 



b All stem leaves alternate 282 



275 a Upper leaves united at their bases to form a cup-like 



disk Silphium. p 234 



b Upper leaves not united at their bases as in a 276 



43 



