178b. Stem-leaves sharply serrate =Coneflower, Rudbeckia speciosa var. sullivantii.=

178c. Stem-leaves entire or sparingly serrate =Black-eyed Susan, Rudbeckia hirta.=

179a. Disk-flowers brown or purple --180.

179b. Disk-flowers yellow --182.

180a. Stem-leaves ovate or ovate-lanceolate; petioles prominent, not winged --181.

180b. Stem-leaves ovate or ovate-lanceolate, contracted at the base into a winged petiole (6-15 dm. high) =Sunflower, Helianthus atrorubens.=

180c. Stem-leaves oblong-lanceolate, very thick and rigid, gradually narrowed to a sessile or short-petioled base (5-20 dm. high) =Sunflower, Helianthus scaberrimus.=

181a. Disk less than 2 cm. wide (3-10 dm. high) =Sunflower, Helianthus petiolaris.=

181b. Disk more than 2.5 cm. wide (1-3 m. high) =Sunflower, Helianthus annuus.=

182a. Leaves all or chiefly at the base (5-10 dm. high) =Sunflower, Helianthus occidentalis.=

182b. Leaves chiefly scattered on the stem --183.

183a. Leaves mainly or all alternate, and not definitely 3-ribbed (1-4 m. high) --184.

183b. Leaves mainly or all opposite, lanceolate to ovate, and 3-ribbed --186.

184a. Stem glabrous =Sunflower, Helianthus grosse-serratus.=

184b. Stem hairy or rough --185.

185a. Leaves hairy beneath, rough above, lanceolate =Sunflower, Helianthus giganteus.=

185b. Leaves rough on both sides, elongated =Sunflower, Helianthus maximiliani.=

186a. Leaves sessile (5-15 dm. high) --187.

186b. Leaves petioled, or narrowed at the base into a petiole (5-30 dm. high) --189.

187a. Leaves wedge-shape at the base =Sunflower, Helianthus doronicoides.=

187b. Leaves rounded at the base --188.

188a. Stem glabrous or nearly so =Sunflower, Helianthus divaricatus.=

188b. Stem densely and softly hirsute =Sunflower, Helianthus mollis.=

189a. Stems rough, p.u.b.escent, or hispid --190.

189b. Stems glabrous or nearly so --193.

190a. Leaves narrowly lanceolate, more than 5 times as long as wide =Sunflower, Helianthus giganteus var. subtuberosus.=

190b. Leaves ovate-lanceolate, not more than 4 times as long as wide --191.

191a. Leaves rounded at base, above the petiole =Sunflower, Helianthus hirsutus.=

191b. Leaves narrowed to the base --192.

192a. Bracts of the involucre spreading =Jerusalem Artichoke, Helianthus tuberosus.=

192b. Bracts all appressed =Sunflower, Helianthus laetiflorus.=

193a. Heads 3 cm. wide or less, including the rays =Sunflower, Helianthus microcephalus.=

193b. Heads 4 cm. wide or more, including the rays --194.

194a. Leaves narrowed at the base into a winged petiole --195.

194b. Petiole slender, not winged =Sunflower, Helianthus decapetalus.=

195a. Leaves green on both sides; bracts longer than the disk =Sunflower, Helianthus tracheliifolius.=

195b. Leaves paler below than above; bracts not longer than the disk --196.

196a. Leaves minutely p.u.b.escent beneath =Sunflower, Helianthus strumosus.=

196b. Leaves conspicuously downy beneath =Sunflower, Helianthus strumosus var. mollis.=

197a. Leaves all basal, the flowers on scaly stalks (2-8 dm. high; flowers whitish, in spring) =Coltsfoot, Petasites palmata.=

197b. Stem-leaves present, opposite --198.

197c. Stem-leaves present, alternate --200.

198a. Leaves ovate, dentate, 2-6 cm. long (2-8 dm. high; summer) (Galinsoga) --199.

198b. Leaves lobed, 10-25 cm. long --113b.

199a. p.u.b.escence spa.r.s.e, appressed =Galinsoga, Galinsoga parviflora.=

199b. p.u.b.escence abundant, spreading =Galinsoga, Galinsoga parviflora var. hispida.=

200a. Leaves dissected or deeply lobed or pinnatifid; pappus never capillary; rays white to pink (3-10 dm. high; summer and autumn) --201.

200b. Leaves entire or serrate --206.

201a. Heads 4-8 mm. wide (Yarrow) --202.

201b. Heads 12-50 mm. wide --203.

202a. Flower-cl.u.s.ters flat-topped =Yarrow, Achillea millefolium.=