Genus 8. 



THISTLE FAMILY. 



365 



tube slender, its limb 5-lobed or 5-cleft. Anthers obtuse at the base. Style-branches elon- 

 gated, obtuse or flattened at the apex. Achenes 10-ribbed, slender, tapering to the base. 

 Pappus of 1 or 2 series of slender barbellate or plumose bristles. [Latin, fringed, from the 

 appearance of the heads.] 



About 35 species, natives of eastern and central North America, known as Blazing Star, or 

 Button Snakeroot from the globular tubers. Type species: Serratula squarrosa L. 



* Bracts of the involucre acute, acuminate or mucronate. 

 Involucre cylindric. or turbinate, 15-60-flowered, its base rounded. 

 Bracts with lanceolate spreading rigid tips. 

 Bracts mucronate, closely appressed. 

 Involucre oblong, or narrowly campanulate, 3-6-flowered. 

 Inner bracts with prolonged petaloid tips. 

 Bracts all acute, mucronate or acuminate. 



Bracts appressed ; pappus-bristles very plumose. 

 Leaves 1" 2" wide; spike usually leafy below. 

 Leaves less than 1" wide; spike mostly naked. 

 Tips of the bracts spreading; pappus-bristles barbellate. 



** Bracts of the involucre rounded, obtuse or acutish. 

 Involucre hemispheric, $' 1' broad, 15-45-flowered ; heads peduncled. 

 Involucre oblong, 2"-$" broad, 5-15-flowered. 

 Bracts obtuse, rounded. 



Involucre rounded at base ; bracts usually not punctate ; heads mostly sessile. 



1. L. squarrosa. 



2. L. cylindrica. 



3. L. clegans. 



punctata. 



acidota. 



pycnostachya. 



. scarwsa. 



Involucre narrowed at base ; bracts usually punctate ; heads peduncled. 

 Leaves, even the lower, narrowly linear; involucre narrowly obovoid, 



Lower leaves linear-oblong; involucre broadly obovoid, 6" 7" high. 

 Bracts acutish, punctate. 



8. L. splcata. 



S"-6" high. 



9. L. graminifolia. 

 ro. L. pilosa. 



11. L. Smallii. 



i. Lacinaria squarrosa (L.) Hill. Scaly 

 Blazing Star. Colic-root. Fig. 4177. 



Serratula squarrosa L. Sp. PI. 818. 1753. 

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

 Liatris squarrosa Willd. Sp. PI. 3: 1634. 1804. 

 Liatris intermedia Lindl. Bot. Reg. pi. ojS. 1825. 

 Lacinaria squarrosa intermedia Porter, Mem. Torr. Club 



5: 314. 1894. 

 Liatris squarrosa var. intermedia DC. Prodr. 5: 129. 



1836. 



Usually stout, i-2 high, pubescent or glabrous. 

 Leaves narrowly linear, rigid, sparingly punctate, 

 3'-6' long, i"-2i" wide; heads sessile or short-pedun- 

 cled, 15-60-flowered, usually few, or sometimes soli- 

 tary, i'-ii' long, 4"-8" thick ; bracts of the involucre 

 imbricated in 5-7 series, lanceolate, rigid, acuminate, 

 glabrous or pubescent, their tips more or less spread- 

 ing when old; flowers purple; pappus very plumose. 



In dry soil, western Ontario to Pennsylvania, Virginia, 

 Florida, South Dakota, Nebraska and Texas. Called also 

 rattlesnake-master. Races differ in pubescence and in 

 size of the heads. June-Sept. 



2. Lacinaria cylindracea (Michx.) 



Kuntze. Cylindric Blazing Star. 



Fig. 4178. 



Liatris cylindracea Michx. Fl. Bor. Am. 2 : 93. 



1S03. 

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

 Lacinaria cylindracea Kuntze, Rev. Gen. PI. 349. 



1891. 



Glabrous or nearly so, stout, i-ii high, 

 sometimes branched above. Leaves narrowly 

 linear, rigid, scarcely punctate, 3'-f long, l"-2 

 wide; heads several or numerous (rarely soli- 

 tary), peduncled, or the lower sessile, turbi- 

 nate-cylindric, i'-i' high, 4"-6" thick, 15-60- 

 flowered; bracts of the involucre imbricated in 

 5 or 6 series, broadly oval, appressed, abruptly 

 acuminate at the apex; flowers purple; pappus 

 very plumose. 



In dry soil, western Ontario to Minnesota, south 

 to Illinois and Missouri. July-Sept. 



