COMPOSITE FAMILY. 191 



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

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

 and autumn, "il 



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

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

 racemed, or occasionally hranching 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 - 5-Jiowered. 



L. tenuifdlia, 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, vi'ith com- 

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

 ing rose-purple tips. 



1- t- Heads large and fewer, cylindrical, many-flowered. 

 L. squarrbsa. Common Blazing-Star; from Pcnn. S. & W. ; 10-3° 

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

 spreading leaf-like tips. 



L. cylindr&cea, 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 — 40flowered, comntbnly an inch broad. 



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

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

 often scarious or purple on the margins. 



-1- t- Heads 3 - 1 5-Jlowered, from i' to ^' long : stem 29 - .'j° high. 



L. pycnost&chya, 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 

 recui-ving purplish tips. 



L. spic&ta, the commonest species ; in low grounds, with 8 - 1 2-flowered 

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

 any obvious tips. 



L. gramiiiif61ia, 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. gr^ilis, 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 conjmh. 

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

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

 long leaves whiclji are vanilla-scented in withering, the heads 7 - 8-flowcred, in- 

 volucre of few scales, and pappus not plumose. 



22. KUHNIA. (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. sctodens, a rather handsome plant, climbs over bushes in low grounds, 

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

 plish flowers, in summer, 'y. 



