127b. Bracts of the involucre in two distinct sets, differing in form or consistency or both — 128.
128a. Leaves entire (3-8 dm. high; late spring and summer) — 120b.
128b. Leaves serrate (late summer and autumn) (Bur Marigold) — 129.
129a. Rays large and conspicuous, 2-3 cm. long (3-10 dm. high) Bur Marigold, Bidens laevis.
129b. Rays 1 cm. long or less — 130.
130a. Outer bracts leaf-like, serrate, 3-8 cm. long (4-15 dm. high) Bur Marigold, Bidens comosa.
130b. Outer bracts 1-2.5 cm. long (2-15 dm. high) — 131.
131a. Heads nodding after flowering Bur Marigold, Bidens cernua.
131b. Heads permanently erect Bur Marigold, Bidens connata.
132a. Heads small, seldom more than 1 cm. wide, including the rays, blooming in late summer and autumn; flowers numerous, crowded in spikes, racemes, corymbs, or panicles (Goldenrod) — 133.
132b. Heads medium size or large, more than 1 cm. and usually exceeding 2 cm. in width, including the rays — 165.
133a. Heads chiefly in clusters or short racemes in the axils of ordinary foliage leaves, or occasionally the upper compacted into a leafy cluster terminating the stem — 134.
133b. Heads crowded at or near the ends of the branches at about the same distance from the base of the panicle, forming a rounded or flat-topped inflorescence — 140.
133c. Heads more or less uniformly distributed along the length of the branches, forming a cylindrical or pyramidal inflorescence, never flat-topped — 146.
134a. Stem and both sides of the leaves more or less pubescent or rough (4-10 dm. high) — 135.
134b. Stem and both sides of the leaves essentially smooth or with very short hairs (3-10 dm. high) — 136.
135a. Rays white Goldenrod, Solidago bicolor.
135b. Rays yellow Goldenrod, Solidago hispida.
136a. Basal leaves abruptly narrowed to winged petioles — 137.
136b. Basal leaves not abruptly narrowed to winged petioles — 138.
137a. Involucre 2-5 mm. long Goldenrod, Solidago latifolia.
137b. Involucre 8-12 mm. long Goldenrod, Solidago macrophylla.
138a. Lower leaves broadly oval, obtuse, thickish, crenate; achenes glabrous Goldenrod, Solidago erecta.
138b. Lower leaves lanceolate, acuminate, thin, sharply serrate; achenes hairy — 139.
139a. Stem usually simple; heads few in very small clusters Goldenrod, Solidago caesia var. axillaris.
139b. Stem usually diffusely branched; heads numerous Goldenrod, Solidago caesia.
140a. Lower leaves ovate, oblong, or oval, pinnately veined (5-15 dm. high) — 141.
140b. Lower leaves linear-lanceolate. 3-5-veined (3-12 dm. high) — 142.
141a. Stem and leaves rough-hairy Goldenrod, Solidago rigida.
141b. Stem and leaves smooth Goldenrod, Solidago ohioensis.
142a. Heads very few in a small cluster; leaves few and scattered Goldenrod, Solidago houghtonii.
142b. Heads very many, in a large cluster; stem very leafy — 143.
143a. Leaves hairy Goldenrod, Solidago graminifolia var. nuttallii.
143b. Leaves smooth — 144.
144a. Leaves folded, 8-20 mm. wide Goldenrod, Solidago riddellii.
144b. Leaves flat, 1-8 mm. wide — 145.
145a. Leaves 4-8 mm. wide, distinctly 3-5-ribbed Goldenrod, Solidago graminifolia.
145b. Leaves 1-4 mm. wide, usually with 1 mid-vein Goldenrod, Solidago tenuifolia.
146a. Only 2-5 stem-leaves below the inflorescence (1-3 dm. high) Goldenrod, Solidago cutleri.
146b. Stem-leaves numerous — 147.
147a. Basal leaves much larger than the greatly reduced or bract-like upper ones — 148.
147b. Leaves essentially uniform in size from base to summit of stem — 157.
148a. Racemes or branches of the panicle either short and arranged along a more or less elongated central axis, or elongated and ascending, scarcely recurved, forming a narrow, more or less elongated panicle — 149.
148b. Racemes or branches of the panicle usually elongated, spreading outwards, usually recurved, forming a widened panicle — 153.
149a. Leaves mostly entire, the upper ones with smaller leaves fascicled in the axils (5-20 dm. high) Goldenrod, Solidago speciosa.
149b. Leaves mostly serrate, at least the basal ones — 150.
150a. Heads on pedicels 5-15 mm. long; achenes pubescent; stems usually clustered (1-5 dm. high, or prostrate) — 151.
150b. Heads on pedicels not over 5 mm. long; achenes smooth or nearly so; stems usually single (6-12 dm. high) — 152.
151a. Basal leaves 7-12 cm. long Goldenrod, Solidago racemosa.
151b. Basal leaves 15-30 cm. long Goldenrod, Solidago racemosa var. gillmani.
152a. Leaves pinnately veined Goldenrod, Solidago uliginosa.
152b. Leaves 3-5-ribbed Goldenrod, Solidago neglecta.
153a. Both sides of the leaf pubescent or rough — 154.
153b. Leaf not pubescent or rough on both sides — 155.
154a. Stem closely pubescent (2-8 dm. high) Goldenrod, Solidago nemoralis.
154b. Stem glabrous (5-12 dm. high) Goldenrod, Solidago juncea var. scabrella.
155a. Leaves rough above, smooth below (6-15 dm. high) Goldenrod, Solidago patula.
155b. Leaves smooth on both sides (5-12 dm. high) — 156.
156a. Branches of the panicle spreading or recurved Goldenrod, Solidago juncea.
156b. Branches of the panicle upright Goldenrod, Solidago juncea var. ramosa.
157a. Stem more or less pubescent or hairy throughout (5-20 dm. high) — 158.
157b. Stem smooth, at least below the inflorescence — 161.
158a. Involucre 2-2.7 mm. long Goldenrod, Solidago canadensis.
158b. Involucre 3-5 mm. long — 159.
159a. Leaves pinnately veined, scabrous above Goldenrod, Solidago rugosa.
159b. Leaves 3-5-ribbed, pubescent but not scabrous above — 160.
160a. Stem and lower side of leaves covered with short hairs; common species Goldenrod, Solidago altissima.
160b. Stem and lower side of leaves with distinct, loose, soft hairs (shore of Lake Superior) Goldenrod, Solidago altissima var. procera.
161a. Involucre 2-2.7 mm. long (5-20 dm. high) — 158a.
161b. Involucre 3-6 mm. long — 162.
162a. Racemes or branches of the panicle either short and arranged along a more or less elongated axis, or elongated and ascending, scarcely recurved, forming a narrow more or less elongated panicle (5-10 dm. high) Goldenrod, Solidago speciosa var. angustata.
162b. Racemes or branches of the panicle usually elongated, spreading outward, usually recurved, forming a widened panicle; leaves distinctly serrate — 163.
163a. Leaves pinnately veined (5-12 dm. high) Goldenrod, Solidago ulmifolia.
163b. Leaves 3-5-ribbed (5-20 dm. high) — 164.
164a. Leaves glabrous on both sides Goldenrod, Solidago serotina.
164b. Leaves slightly pubescent beneath Goldenrod, Solidago serotina var. gigantea.
165a. Ray-flowers pistillate (the 2-lobed style protrudes from their base) — 166.
165b. Ray-flowers with neither stamens nor pistil — 174.
166a. Principal leaves more than 2 dm. long (1-3 m. high; summer) — 167.
166b. Principal leaves less than 1.5 dm. long — 168.
167a. Leaves deeply lobed Compass Plant, Silphium laciniatum.
167b. Leaves toothed or serrate Elecampane, Inula helenium.
168a. Leaves narrowly linear (3-6 dm. high; late summer) Sneezeweed, Helenium tenuifolium.
168b. Leaves of a broader shape — 169.
169a. Heads 1-2 cm. wide; flowers in spring and early summer (2-8 dm. high) (Ragwort) — 170.
169b. Heads 2-5 cm. wide; flowers in late summer and autumn — 173.
170a. Basal leaves cordate at base Ragwort, Senecio aureus.
170b. Basal leaves narrowed to the base — 171.
171a. Basal leaves obovate Ragwort, Senecio obovatus.
171b. Basal leaves oblong Ragwort, Senecio balsamitae.
172a. Introduced annual in waste places (1-4 dm. high; spring and summer) Groundsel, Senecio vulgaris.
172b. Native biennial in moist ground (3-8 dm. high; summer) Squaw Weed, Senecio discoideus.
173a. Leaves 2-5 cm. long, sharply spinulose-serrate; involucre viscid (3-6 dm. high; summer) Gum Plant, Grindelia squarrosa.
173b. Leaves 5-12 cm. long, merely serrate; involucre gray-pubescent (5-15 dm. high; late summer) Sneeze Weed, Helenium autumnale.
174a. Disk hemispherical or oblong-cylindrical (Summer) — 175.
174b. Disk flat or somewhat convex (Sunflower) (summer and autumn) — 179.
175a. Disk yellow or greenish-yellow (1-3 dm. high) — 176.
175b. Disk gray-brown or purple (5-15 dm. high) — 177.
176a. Principal stem-leaves pinnately divided Golden Glow, Rudbeckia laciniata.
176b. Principal stem-leaves merely serrate Yellow Ironweed, Actinomeris alternifolia.
177a. Rays drooping; leaves pinnately divided Gray-headed Coneflower, Lepachys pinnata.
177b. Rays spreading when in bloom — 178.
178a. Lower leaves deeply 3-lobed Coneflower, Rudbeckia triloba.
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, pubescent, 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 pubescent 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. Pubescence sparse, appressed Galinsoga, Galinsoga parviflora.
199b. Pubescence 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-clusters flat-topped Yarrow, Achillea millefolium.
202b. Flower-clusters very convex Yarrow, Achillea lanulosa.
203a. Principal leaves pinnatifid — 213a.
203b. Principal leaves 1-3 times pinnately parted or dissected — 204.
204a. Leaf-segments very narrowly linear; leaves 2-3-pinnate — 205.
204b. Leaf-segments linear or lanceolate; heads 2.5-5 cm. wide Camomile, Anthemis arvensis.
204c. Leaf-segments ovate to ovate-oblong; heads 1-2 cm. wide Feverfew, Chrysanthemum parthenium.
205a. Foliage strongly scented Dog Fennel, Anthemis cotula.
205b. Foliage not ill-scented Wild Camomile, Matricaria inodora.
206a. Heads 3-6 mm. broad, including the rays (summer and autum) — 207.
206b. Heads 7 mm. broad or larger, including the rays — 209.
207a. Rays purple (1-4 dm. high) Horse Weed, Erigeron divaricatus.
207b. Rays white — 208.
208a. Leaves obovate to oblong (3-10 dm. high) — 135a.
208b. Leaves linear or narrowly lanceolate (2-25 dm. high) Horse Weed, Erigeron canadensis.
209a. Pappus none, or minute and not of hairs (summer and autumn) — 210.
209b. Pappus of hairs — 214.
210a. Disk-flowers purple or brown (4-12 dm. high; rays pink) (Purple Coneflower) — 211.
210b. Disk-flowers yellow or nearly white — 212.
211a. Leaves ovate or ovate-lanceolate, most of them serrate Purple Coneflower, Brauneria purpurea.
211b. Leaves narrowly lanceolate, gradually narrowed at the base, entire Purple Coneflower, Brauneria pallida.
212a. Rays broadly obovate; heads 1-2 cm. wide (3-6 dm. high) Sneezewort, Achillea ptarmica.
212b. Rays oblong or narrowly elliptical — 213.
213a. Leaves serrate (3-10 dm. high) Ox-eye Daisy, Chrysanthemum leucanthemum var. pinnatifidum.
213b. Leaves entire (8-25 dm. high) Boltonia, Boltonia asteroides.
214a. Involucral bracts all the same length or nearly so and narrow, or with a few short outer ones; plants blooming in spring and summer, or a few plants persisting in bloom until autumn (Fleabane) — 215.
214b. Involucral bracts unequal, the outer successively shorter (or rarely nearly equal), loosely or closely overlapping; plants 3-15 dm. high, blooming in late summer and autumn (Aster) — 221.
215a. Rays short and inconspicuous, barely longer than the pappus (1-5 dm. high; summer) Fleabane, Erigeron acris var. asteroides.
215b. Rays conspicuous, spreading, 3 mm. long or more — 216.
216a. Rare plants of the Northern Peninsula, with entire leaves and stems 1-5 dm. high, from a thick woody root (flowers white or purple, summer) — 217.
216b. Common species, with erect stems from fibrous roots; leaves toothed (except in one species) — 218.
217a. Heads 3-5 cm. wide; rays about 100 Fleabane, Erigeron glabellus.
217b. Heads 1-2 cm. wide; rays 20-30 Fleabane, Erigeron hyssopifolius.
218a. Stem unbranched, except for the peduncles; leaves chiefly basal; heads 1-9 (2-5 dm. high; flowers pale-purple, spring) Fleabane, Erigeron pulchellus.
218b. Stem branched; principal leaves on the stem; heads usually numerous (3-12 dm. high; spring and summer) — 219.
219a. Stem-leaves linear, entire Fleabane, Erigeron ramosus.
219b. Stem-leaves ovate-lanceolate, the principal ones toothed — 220.
220a. Rays 100 or more, light-purple or pink Fleabane, Erigeron philadelphicus.
220b. Rays much fewer, white Fleabane, Erigeron annuus.
221a. Basal leaves petioled and heart-shape at the base — 222.
221b. Basal leaves not petioled; stem-leaves with heart-shape clasping bases — 231.
221c. Basal and stem-leaves sessile or petioled, but never heart-shape or clasping — 240.
222a. Rays white or violet — 223.
222b. Rays blue — 225.
223a. Plant glandular, especially on the pedicels and branches of the inflorescence Aster, Aster macrophyllus.
223b. Plant not glandular — 224.
224a. Leaves rough above Aster, Aster schreberi.
224b. Leaves smooth above Aster, Aster divaricatus.
225a. Stem-leaves clasping the stem by a cordate base Aster, Aster undulatus.
225b. Stem-leaves not cordate-clasping — 226.
226a. Leaves entire — 227.
226b. Leaves serrate — 228.
227a. Leaves glabrous above Aster, Aster shortii.
227b. Leaves rough above Aster, Aster azureus.
228a. Involucre 4-6 mm. long — 229.
228b. Involucre 6-10 mm. long — 230.
229a. Leaves rough; petioles mostly winged Aster, Aster lowrieanus.
229b. Leaves smooth; petioles slender, not winged Aster, Aster cordifolius.
230a. Heads few, seldom more than 10, in a loose spreading cluster Aster, Aster lindleyanus.
230b. Heads numerous, in a rather elongate crowded cluster Aster, Aster sagittifolius.
231a. Stem hirsute or rough-pubescent — 232.
231b. Stem smooth, or essentially so — 236.
232a. Leaves conspicuously serrate Aster, Aster puniceus.
232b. Leaves entire or nearly so — 233.
233a. Leaves narrowed toward the base and barely clasping, linear or oblong-linear — 234.
233b. Leaves ovate-oblong or lanceolate, with a broad conspicuously clasping base — 235.
234a. Involucre pubescent but not glandular Aster, Aster amethystinus.
234b. Involucre glandular Aster, Aster oblongifolius.
235a. Involucre very glandular and viscid; rays very numerous, violet-purple; leaves lanceolate Aster, Aster novae-angliae.
235b. Involucre slightly glandular or not at all; rays 20-30, generally blue-purple; leaves ovate-oblong Aster, Aster patens.
236a. Leaves of a linear type — 237.
236b. Leaves broader than linear, at least 1 cm. wide — 238.
237a. Bracts narrow, approximately equal in length — 253a.
237b. Bracts of several lengths, the outer successively shorter — 256a.
238a. Leaves smooth above Aster, Aster laevis.
238b. Leaves rough above — 239.
239a. Leaves contracted below the middle and then abruptly dilated to the clasping base Aster, Aster prenanthoides.
239b. Leaves gradually narrowed toward the base Aster, Aster puniceus.
240a. Rays conspicuous — 241.
240b. Rays minute or wanting Aster, Aster angustus.
241a. Stems and leaves gray with a silky pubescence Aster, Aster sericeus.
241b. Stem and leaves green, not silky — 242.
242a. Bracts glandular-viscid; rays violet Aster, Aster oblongifolius.
242b. Bracts bristly-ciliate — 243.
242c. Bracts smooth or pubescent, not glandular or bristly-ciliate — 244.
243a. Leaves crowded, rigid; rays white Aster, Aster multiflorus.
243b. Leaves not crowded and rigid; rays blue — 234a.