Genus 8. 



THISTLE FAMILY. 



6. Lacinaria pycnostachya (Michx.) Kuntze. 



Prairie or Hairy Button-Snakeroot. 

 Fig. 4182. 



Liatris pycnostachya Michx. Fl. Bor. Am. 2: 91. 1S03. 

 Lacinaria pycnostachya Kuntze, Rev. Gen. PI. 349. 1891. 



Hirsute-pubescent above, usually glabrous below, 2-$ 

 high, very leafy. Lower leaves linear-lanceolate, nar- 

 rowed below the middle into a slender margined petiole, 

 acuminate at the apex, often 1 long and i' wide, the 

 upper much smaller, linear-subulate, rigid, punctate; 

 spikes very dense, 6'-i8' long; heads 4"-6" long, 3- 

 6-flowered ; involucre oblong or cylindric, its bracts 

 oblong, pubescent and ciliate with acute, spreading, 

 colored tips; flowers purple; pappus barbellate or 

 roughened, scarcely plumose. 



On prairies, Indiana to Minnesota, Nebraska, Kentucky, 

 Louisiana and Texas. Aug.-Sept. 



7. Lacinaria scariosa (L.) Hill. Large 

 Button-Snakeroot. Fig. 4183. 



Serratula scariosa L. Sp. PI. 818. 1753. 

 Lacinaria scariosa Hill, Hort. Kew. 70. 1769. 

 Liatris scariosa Willd. Sp. PI. 3: 1635. 1S04. 

 Liatris squarrulo sa Michx. Fl. Bor. Am. 2 : 92. 1803. 



Finely pubescent, at least above, i-6 high. 

 Lower leaves oblanceolate, spatulate or oblong- 

 lanceolate, narrowed into a margined petiole, 

 acute or obtusish at the apex, often 1 long 

 and l wide; upper leaves linear or linear- 

 lanceolate, acute, or sometimes very obtuse, 

 much smaller, all densely punctate ; heads hemi- 

 spheric, l'-i' broad, 15-45-flowered, on stout 

 peduncles 2"-2' long, or sometimes sessile ; 

 bracts of the involucre imbricated in 5 or 6 

 series, spatulate-linear, oblanceolate or obovate, 

 rounded at the apex, appressed, their tips dry 

 and scarious, often colored; flowers bluish 

 purple; pappus barbellate. 



In dry soil, Maine to Florida, western Ontario, 

 Manitoba, Nebraska and Texas. Consists of many 

 races, differing in leaf-form and size of heads. 

 Called also blue blazing-star, gray feather, rattle- 

 snake-master, devil's-bite. Aug.-Sept. 



8. Lacinaria spicata (L.) Kuntze. 

 Dense Button-Snakeroot. Gay 

 Feather. Devil's Bit. Fig. 4184. 



Serrulata spicata L. Sp. PI. 819. 1753. 

 Liatris spicata Willd. Sp. PI. 3: 1636. 1804. 

 ?Liatris pumila Lodd. Bot. Cab. pi. 147. 1821. 

 L. spicata Kuntze, Rev. Gen. PI. 349. 1891. 



Glabrous or nearly so, 2-6 high. Lower 

 leaves linear-lanceolate or linear-oblong, 

 usually blunt-pointed, sometimes i long 

 and 5" wide, the upper linear or even subu- 

 late, somewhat or obscurely punctate; spike 

 generally dense, 4'-i5' long ; heads short- 

 oblong or cylindric, 5-13-flowered, 2"-4" 

 broad, mostly sessile ; involucre subcam- 

 panulate, rounded or obtuse at the base, 

 its bracts appressed, oblong, obtuse and 

 scarious-margined at the apex, obscurely 

 punctate, imbricated in 4-6 series; flowers 

 blue-purple, occasionally white; pappus 

 roughened or barbellate. 



In moist soil, Massachusetts to Florida, On- 

 tario, Wisconsin, Kentucky, Louisiana and Ari- 

 zona. Called also rough- or backache-root, 

 throat-wort, prairie-pine, colic-root. Aug.-Oct. 



Lacinaria kansana P.ritton, of Kansas, differs in having a short, very dense spike, a more leafy 

 stem, the involucral bracts purple and the pappus plumose. 



