16b. Basal leaves toothed, lobed, or pinnatifid (spring and summer) --17.

17a. Heads 8-14 mm. wide (1-4 dm. high) =Dwarf Dandelion, Krigia virginica.=

17b. Heads 25-50 mm. wide (1-6 dm. high) (Dandelion) --18.

18a. Outer involucral bracts reflexed =Dandelion, Taraxac.u.m officinale.=

18b. Outer involucral bracts erect or spreading =Dandelion, Taraxac.u.m erythrospermum.=

19a. Pappus none; heads about 1 cm. wide (4-10 dm. high; summer) =Nipplewort, Lapsana communis.=

19b. Pappus of an inner row of bristles and an outer row of short scales; heads about 3 cm. wide (3-8 dm. high; early summer) =Cynthia, Krigia amplexicaulis.=

19c. Pappus of feathery bristles (summer) --20.

19d. Pappus of simple bristles --25.

20a. Flower-stalk scaly, without foliage leaves (2-6 dm. high) =Fall Dandelion, Leontodon autumnalis.=

20b. Stem leafy (3-10 dm. high) --21.

21a. Leaves entire, linear-lanceolate =Meadow Salsify, Tragopogon pratensis.=

21b. Leaves serrate, oblong-lanceolate =Picris, Picris hieracioides.=

22a. Pappus tawny in color (1-3 m. high) --23.

22b. Pappus white --24.

23a. Leaves pinnatifid =Wild Lettuce, Lactuca spicata.=

23b. Leaves undivided, dentate =Wild Lettuce, Lactuca spicata var. integrifolia.=

24a. Upper leaves entire; heads about 1.5 cm. wide (5-10 dm. high) =Wild Lettuce, Lactuca pulch.e.l.la.=

24b. Upper leaves dentate or lobed; heads about 1 cm. wide (1-3 m.

high) =Wild Lettuce, Lactuca floridana.=

25a. Achene tipped with a slender beak, bearing the pappus at its summit (summer) (Wild Lettuce) --26.

25b. Achene without a beak --29.

26a. Leaves hirsute or hispid on the mid-veins beneath --27.

26b. Leaves glabrous --28.

27a. Leaves p.u.b.escent on both sides (1-2 m. high) =Wild Lettuce, Lactuca hirsuta.=

27b. Leaves glabrous, except on the mid-vein (5-15 dm. high) =Wild Lettuce, Lactuca scariola var. integrata.=

28a. Leaves entire or spa.r.s.ely toothed (1-2 m. high) =Wild Lettuce, Lactuca sagittifolia.=

28b. Leaves chiefly sinuate-pinnatifid (1-3 m. high) =Wild Lettuce, Lactuca canadensis.=

29a. Flowers white, cream-color, or purplish (summer and autumn) (Rattlesnake Root) --30.

29b. Flowers bright-yellow or orange --33.

30a. Heads nodding (6-20 dm. high) --31.

30b. Heads pointing in various directions, in spike-like panicles; involucres p.u.b.escent (5-15 dm. high) =Rattlesnake Root, Prenanthes racemosus.=

31a. Heads with 5-7 flowers in each =Rattlesnake Root, Prenanthes altissima.=

31b. Heads with 8-12 flowers --32.

31c. Heads with 20 or more flowers =Rattlesnake Root, Prenanthes crepidinea.=

32a. Pappus dark reddish-brown =Rattlesnake Root, Prenanthes alba.=

32b. Pappus pale-brown or nearly white =Rattlesnake Root, Prenanthes trifoliata.=

33a. Pappus tawny or brown in color (summer and autumn) (Hawkweed) --34.

33b. Pappus white --42.

34a. Heads 2.5 cm. in diameter, or larger --35.

34b. Heads 1-2 cm. in diameter (4-10 dm. high) --37.

35a. Leaves all basal (1-4 dm. high) =Hawkweed, Hieracium pilosella.=

35b. Stem-leaves present (4-15 dm. high) --36.

36a. Leaves rounded at the sessile base =Hawkweed, Hieracium canadense.=

36b. Leaves narrowed toward the base =Hawkweed, Hieracium umbellatum.=

37a. A rosette of basal leaves conspicuous at flowering time --38.

37b. No rosette of basal leaves at time of flowering --41.

38a. Leaves glabrous on the upper side --39.

38b. Leaves hairy on the upper side --40.

39a. Stem glabrous, leafless or with one or two leaves =Hawkweed, Hieracium venosum.=

39b. Stem with several leaves, hairy below =Hawkweed, Hieracium marianum.=