COMPOSITE. (COMPOSITE FAMILY.) 277 



1. T. CUSpid&tum, Pursh. Leaves lanceolate, elongated, tapering to a 

 sharp point, woolly on the margins ; scales of the involucre lanceolate, sharp- 

 pointed. Prairies, Wisconsin, N. Illinois, and westward. April, May. 



77. HIEBACIUM, Tourn. HAWKWEED. 



Heads 12 -many-flowered. Involucre more or less imbricated. Achenia 

 short, oblong or columnar, striate, not beaked. Pappus a single row of tawny 

 and fragile capillary rough bristles. Perennial herbs, with entire or toothed 

 leaves, and single or panicled heads of mostly yellow flowers ; in summer and 

 early autumn. (Name from lepa, a hawk.) 



* Heads large and broad : involucre imbricated : achenia tapering towards the base. 



1. H. Canadense, Michx. (CANADA HAWKWEED.) Stems simple, 

 leafy, corymbed at the summit (l-3 high) ; leaves sessile, lanceolate or ovate- 

 oblong, acute, remotely and very coarsely toothed, somewhat hairy, the upper- 

 most slightly clasping. Dry woods, northward. 



* # Heads small : involucre cylindrical, scarcely imbricated. 



2. H. SCabrum, Michx. (ROUGH H.) Stem rather stout (l-3 high), 

 leafy, rough-hairy ; the stiff panicle at first racemose, at length rather corymbose ; 

 the thickish peduncles and the hoary 40 - 50-flowered 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. 



3. H. longipilum, Torr. (LONG-BEARDED H.) Stem wand-like, sim- 

 ple, stout (2 -3 high), very leafy towards the base, naked above, and bearing a 

 small racemed panicle ; the lower portion and both sides of the oblong-lanceo- 

 late or spatulate entire leaves thickly clothed with very long and upright bristles 

 (often 1' long) ; peduncles and 20 - 30-flowered involucre glandular-bristly ; ache- 

 nia spindle-shaped, narrowed at the apex. Prairies, Michigan to Wisconsin and 

 southwestward. Heads intermediate between the last and the next. 



4. H. Gron6vii, L. (HAIRY H.) Stem wand-like, mostly simple, leafy 

 and very hairy below, naked above and forming a long and narrow panicle ; leaves 

 oblong or obovate, nearly entire, hairy ; the slender peduncles and the 20 - 30- 

 flowered involucre sparingly glandular-bristly; achenia spindle-shaped, with a 

 very taper summit. Dry sterile soil : common, especially southward. Varies 

 from l-4 high. The small heads and almost beaked fruit distinguish the 

 largest forms from No. 2, and small naked-stemmed states from the next. 



5. H. ven6sum, L. (RATTLESNAKE-WEED.) Stem or scape (l-2 

 high) 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 above with purple veins ; peduncles very slender ; involucre 20-flowered ; 

 achenia linear, not tapering upwards. Var. SUBCAULESCENS has the stem 

 more or less leafy next the base. Dry plains and pine woods : common. 



6. H. paniculatum, L. (PANICLED H.) Stem slender, leafy, diffusely 

 branched, hairy below (2 -3 high); leaves lanceolate, acute at both ends, 

 slightly toothed, smooth ; heads in a loose panicle (very small), on slender and 



