238 ELEMENTS OF BOTANY. 



rigid, smooth or hairy, 8-5-ribbed; heads few, about 1 in. long, in 

 a leafy-bracted spike, many-flowered; bracts in several rows, with 

 rigid, acuminate, spreading tips ; lobes of the corolla hairy ; pappus 

 very plumose. June-September. On dry soil. 



2. L. ELEGANS (Walt.) Kuntze. Showy Blazing-stak. Stem 

 erect, tomentose, simple, 2-3 ft. high ; leaves very numerous, linear, 

 punctate, the upper small and bract-like; heads very numerous, 

 showy, 4-5-flowered, in a long and dense spike or raceme ; bracts 

 numerous, in 2-3 series, the tips of the inner ones spreading and 

 petal-like, the outer ones loose ; pappus very plumose. July-August. 

 On dry pine barrens. 



3. L. scARiosA (L.) Hill. Button Snakeroot. Stem stout, 

 simple, pubescent, 3-6 ft. high; leaves pubescent and punctate, the 

 lower spatulate to oblanceolate, the upper linear and acute ; heads 

 large, often 1 in, wide, many-flowered, sessile or short-peduncled, in 

 long spikes ; flowers bluish purple ; involucral bracts in several 

 series, obtuse, the margins colored; pappus short-plumose. July- 

 September. On dry soil. 



4. L. spicata (L.) Kuntze. Spiked Button Snakeroot. Stem 

 erect, smooth, simple, very leafy, 3-6 ft. high ; lower leaves linear, 

 obtuse, erect, 1 ft. or more in length, 3-5-riblied, the upper smaller 

 and bract-like ; heads in a long and dense spike, cylindrical, 8-12- 

 flowered; flowers blue-purple to white; involucral bracts in 4-6 

 rows, smooth, purple, obtuse and scarious-margined at the apex; 

 pappus short-plumose. July-September. On moist soil. 



IV. TRILISA. 



Perennial from a fibrous root ; leaves alternate ; heads in 

 corymbs or panicles, few-flowered, discoid ; bracts in 2-3 

 rows, the outer shorter ; receptacle naked ; corolla 5-lobed ; 

 achenes oblong, 10-ribbed ; pappus of barbed bristles. 



T. odoratissima (Walt.) Cass. Deer-tongue. Vanilla Plant. 



Stem erect, stout, smooth and glaucous, often pm'ple, branched 

 above, 2-4 ft. high; lower leaves oblong to spatulate, 3-5-ribbed, 

 thick, smooth, entire, petioled, the upper smaller and sessile ; heads 

 in corymbs, 7-9-flowered, flowers purple ; bracts oblong, obtuse ; 

 achenes pubescent; pappus minutely bearded. July-September.. In 

 flat pine barrens. The withering plants strongly vanilla-scented. 



V. SOLIDAGO. 



Perennial herbs, or rarely shrubby ; leaves alternate, entire 

 or toothed ; heads small, radiate ; involucral bracts imbri- 



