COMPOSITE. (COMPOSITE FAMILY.) 237 



* * Heads small : involucre cylindrical, scarcely imbricated. 



2. II. scabrum, Michx. (ROUGH HAWKWEED.) Stem rather stout 

 (l-3high), leafy, rough-hairy; the stiff flexuous panicle at first racemose, 

 at length ratlin- corymbose; the thickish peduncles and the hoary 40 - 50-llow- 

 ered involucre densely clothed with dark glandular bristles ; achenia columnar, not 

 tapering at the summit ; leaves obovate or oval, nearly entire, hairy. Dry open 

 woods ; common, especially northward. Aug. 



3. II. loiigipilum, Torr. (LONG-BEARDED HAWKWEED.) Stem wand 

 like, simple, stout (2 -3 high), very leafy toivards the base, naked above, and 

 bearing a small racemed panicle ; the lower portion and both sides of the ob- 

 long-lanceolate or spatulate entire leaves thickly clothed with very long and upright 

 bristles; peduncles with the 20 - 30-flowered involucre glandular-bristly; achenia 

 spindle-shaped, narrowed at the apex. Prairies, Michigan to Illinois, and west- 

 ward. Aug. Heads intermediate between the last and the next. Bristles 

 straight and even, as if combed, often 1' long ! 



4. II. Gronovii, L. (HAIRY HAWKWEED.) Stem wand-like, mostly 

 simple, leafy and very hairy beloiv, naked above and forming a long and narrow 

 panicle; leaves oblong or obovate, nearly entire, hairy ; the slender peduncles 

 and the 20 - 30-flowercd involucre sparingly glandular-bristly ; achenia spindle- 

 shaped, with a very taper summit. Dry sterile soil ; common, especially south- 

 ward. Aug. Varies from 1 4 high; with small heads and almost beaked 

 fruit, which well distinguishes the largest forms from No. 2, and the smallest 

 naked-stemmed states from the next. 



5. II. venosuin, L. (RATTLESNAKE-WEED.) Stem or scape naked or 

 with a single leaf, smooth and slender, forking above into a spreading loose corymb ; 

 root-leaves obovate or oblong, nearly entire, scarcely petioled, thin and pale, 

 purplish and glaucous underneath (often hairy along the midrib), marked with 

 purple veins ; peduncles very slender ; involucre 20-flowered ; achenia linear, not 

 tapering above. Var. SUBCAULESCENS has the stem more or less leafy next 

 the base. Dry plains and pine woods ; common. Plant 1 - 2 high. 



6. II. pailiculatlini, L. (PANICLED HAWKWEED.) Stem slender, 

 leafy, diffusely branched, hairy below (2 -3 high) ; leaves lanceolate, acute at 

 both ends, slightly toothed, smooth ; heads (very small) in a loose panicle, on slen- 

 der diverging peduncles, 12 - 20-JJowered ; achenia short, not tapering at the sum- 

 mit. Open woods ; rather common. 



7"7. NABALUS, Cass. RATTLESNAKE-ROOT. 



. Heads few - many-flowered. Involucre cylindrical, of 5 to 14 linear scales in 

 a single row, and a few small bractlets at the base. Achenia linear-oblong, stri- 

 ate or grooved, not contracted at the apex. Pappus of copious straw-color or 

 brownish roughish capillary bristles. Perennial herbs, with upright leafy stems 

 arising from spindle-shaped (extremely bitter) tubers, very variable leaves, and 

 racemose-panicled mostly nodding heads. Flowers greenish-white or cream- 

 color, often tinged with purple. (Name probably from vafiXa, a harp, in allu- 

 sion to the lyrate leaves which these plants sometimes present.) Species of 

 Preuauthes, L. See Addend. 



