29. S. Missouriénsis, Nutt. Smooth throughout (1--3° high); _leaves linear-lanceolate_, or the lower broadly lanceolate, tapering to both ends, with very rough margins; teeth, if any, sharp and rigid; heads and dense crowded racemes nearly as in n. 28; _achenes nearly glabrous_.--Dry prairies, from Wisc. and Ind. south and westward.--Heads 1½--2´´ long. 30. S. Shórtii, Torr. & Gray. Stem slender, simple (2--4° high), minutely roughish-pubescent above; _leaves_ (the larger 2--3´ long) _oblong-lanceolate_, acute, the lower mostly serrate with a few fine teeth; racemes mostly short in a crowded panicle; _achenes silky-pubescent_.--Rocks at the Falls of the Ohio; Ark.--A handsome species; heads 3´´ long, narrow. [b.] _Leaves thinner; involucral scales thin, chiefly linear, obtuse._ 31. S. serótina, Ait. _Stem_ stout (2--7° high), _smooth, often glaucous; leaves quite smooth both sides_, lanceolate, taper-pointed, very sharply serrate, except the narrowed base, rough-ciliate; the ample panicle pubescent; _rays 7--14, rather long_. (S. gigantea, of previous ed.)--Copses and fence-rows; common, and presenting many varieties. Seldom very tall. Var. gigantèa, Gray. Commonly tall, 5--8° high; leaves more or less pubescent or hispidulous beneath. (S. gigantea, _Ait._; S. serotina of previous ed.)--Thickets and low grounds, Can. to Tex. 32. S. rupéstris, Raf. _Stem smooth, slender_, 2--3° high; _leaves linear-lanceolate, tapering both ways, entire_ or nearly so; panicle narrow; _heads very small; rays 4--6, very short_.--Rocky river-banks, W. Va. to Ky. and Ind. [=][=] _Pubescent (at least the stem) or hispidulous-scabrous._ 33. S. Canadénsis, L. _Stem rough-hairy_, tall and stout (3--6° high); _leaves lanceolate_, pointed, sharply serrate (sometimes almost entire), _more or less pubescent beneath and rough above; heads small; rays very short_.--Borders of thickets and fields; very common.--Varies greatly in the roughness and hairiness of the stem and leaves, the latter oblong-lanceolate or elongated linear-lanceolate;--in var. PRÒCERA, whitish-woolly underneath; and in var. SCÀBRA also very rough above, often entire, and rugose-veined. 34. S. nemoràlis, Ait. _Clothed with a minute and close grayish-hoary_ (soft or roughish) _pubescence_; stem simple or corymbed at the summit (½--2½° high); leaves _oblanceolate or spatulate-oblong_, the lower somewhat crenate-toothed and tapering into a petiole; racemes numerous, dense, at length recurved, forming a large and crowded compound raceme or panicle which is usually turned to one side; scales of the involucre linear-oblong, appressed; rays 5--9.--Dry sterile fields; very common. Flowers very bright yellow, beginning early in Aug.--Var. INCÀNA, Gray, of Minn., and westward, is a dwarf form, with rigid oval or oblong leaves, rather strongly serrate or entire, and the clusters of heads in a dense oblong or conical thyrse.