COMPOSITE FAMILY. 191 



21. LIATRIS, BUTTON-SNAKEROOT or BLAZING-STAR. (An 

 unexplained name. ) Chiefly in pine-barrens or sandy soil. Fl. late summer 

 and autumn, y. 



§ 1. bteni commonlij wand-like and simple, rising from a round corm or short tuber, 

 very leafy with narrow and entire often grass-like leaves : heads spiked or 

 rucemed, or occasionally In-anching into a panicle, with imbricated involucre: 

 lobes of the rose-purple corolla long and slender. 



* Bristles of the pappus plainly plumose to the naked eye. 



■I- Heads small, only 4 - h-Jlowered. 



L. tenuif61ia, in S. pine-barrens, has very slender mostly thread-shaped 

 leaves, stem 2° - 4° high, very slender raceme, and scales of involucre erect and 

 pointed. 



L. ^legans, from Virginia S. ; 2° high, often hairy or downy, with com- 

 pact spike, short lanceolate or linear leaves, and scales of involucre with spread- 

 ing rose-purple tips. 



■^ •*- Heads large and fewer, cylindrical, many-flowered. 

 L. squarrbsa, Common Blazing-Star; from Penn. S. & W. ; l°-3° 

 high, with linear leaves, few heads about 1' long, and scales of involucre with 

 spreading leaf-like tips. 



L. eylindr&,eea, from W. Canada S. W., smaller than the preceding, 

 6' - 18' high, the narrow heads with short and rounded appressed tips. 

 * * Bristles of the pappus not plainly plumose to the naked eye. 

 •*- Heads 30 — iO-flowered, commonly an inch broad. 



Ii. Scari6sa, with stout stem 2° - 5° high, lanceolate leaves, or the lower 

 spatuIate-oblong,'and very numerous scales of the involucre with rounded tips, 

 often scarious or purple on the margins. 



-I- -1- Heads 3 - \h'-flowered, from i' to ^' long: stem 2° - 5° high. 



L. pyenostichya, in prairies W., with linear or lance-linear leaves, and 

 a very dense spike of about 5-flowered heads, the scales of the involucre with 

 recurving purplish tips. 



L. spic&ta, the commonest species; in low grounds, with 8-I2-flowered 

 heads crowded in a long spike, the oblong and blunt scales of involucre without 

 any obvious tips. 



Ii. gramillifdlia, in wet pine-barrens from New Jersey S., has 7 - 12- 

 flowered heads in a looser spike or raceme, the rigid appressed scales blunt or 

 slightly pointed. ' 



L. gracilis, from N. Carolina S., with spreading leaves, the lower lance- 

 oblong and long-petioled, the others linear and short, and 3 - 7-flowered small 

 heads on spreading pedicels. 



§ 2. No tuber or corm : leaves broad: heads small, in a corymb. 



L. Odoratissima, Vanilla-plant of low pine-barrens S. (also wrongly 

 called Hocnd's-tongce) : 2°-3° high, very smooth, with pale obovate or ob- 

 long leaves which are vanilla-scented in withering, the heads 7 - 8-flowered, in- 

 volucre of few scales, and pappus not plumose. 



22. KUHIflA. (Named by Linnaeus for Dr. Kuhn of Pennsylvania.) 



K. eupatorioides, the only species from New Jersey to Wisconsin S., 

 is a rather homely herb, with lanceolate leaves, and panicled or corymbed small 

 heads of flowers, in autumn, y. 



23. MIKANIA, CLIMBING HEMPWEED. (Named for a Bohemian 

 botanist, Prof Mikan.) 



M. SC&ndens, a rather handsome plant, climbs over bushes in low grounds, 

 with triangular-heart-shaped or halberd-shaped leaves, and small heads of puiv 

 plish flowers, in summer. % 



