GENUS 73. THISTLE FAMILY. 50! 
2. Thelesperma intermédium Rydb. 
Stiff Thelesperma. Fig. 4520. 
Thelesperma intermedium Rydb. Bull. Torr. Club 
27: 631. 1900. 
Perennial from a deep woody root and slen- 
der rootstocks; stem rigid, usually much 
branched, 1°-14° high. Leaves usually numer- 
ous, 13-2’ long, bipinnately divided into entire, 
rigid, linear segments, but less compound than 
those of the preceding species; outer bracts of 
the involucre lanceolate-subulate, usually much 
shorter than the inner ones, which are united 
to about the middle: rays and achenes similar 
to those of the preceding. 
In dry soil, on plains, Nebraska and Wyoming 
to Colorado and New Mexico. In our first edition 
included in T. ambiguum A. Gray, of the South- 
west. June-Aug. 
3. Thelesperma gracile (Torr.) A. Gray. 
Rayless Thelesperma. Fig. 4521. 
Bidens gracilis Torr. Ann. Lye. N. Y. 2: 21g. 1Bay. 
T. gracile A. Gray, Kew. Journ. Bot. 1: 252. 1849. 
Perennial from a deep root; stem rigid, branched, 
1°-3° high, the branches nearly erect. Leaves rigid, 
erect or ascending, 2-3’ long, pinnately or bipin- 
nately divided into linear segments, or the upper 
linear and entire; heads 6’-10” broad; rays usually 
none, sometimes present and 2-3” long; outer bracts 
of the involucre 4-6, oblong.or ovate, mostly ob- 
tuse, very much shorter than the inner ones, which 
are united to the middle or beyond; disk yellow or 
brownish; outer achenes slightly papillose; pappus 
awns longer than the width of the summit of the 
achene. 
On dry plains, Nebraska and Wyoming to Texas, 
northern Mexico and Arizona. May-Aug. 
74. GALINSOGA Cav. Icon. 3: 41. 1704. 
Annual branching herbs, with opposite, mostly petioled, dentate or entire leaves, and 
small peduncled heads of both tubular and radiate flowers, terminal and in the upper axils. 
Involucre hemispheric or broadly campanulate, its bracts in 2 series, ovate, obtuse, mem- 
branous, striate, nearly equal, or the outer shorter. Receptacle conic or elongated, its thin 
chaff subtending the disk-flowers. Ray-flowers white or red, pistillate, fertile, the rays 4 or 
5, Short. Disk-flowers yellow, perfect, the corolla 5-toothed. Anthers minutely sagittate at 
the base. Style-branches tipped with acute appendages. Achenes angled, or the outer ones 
flat. Pappus of the disk-flowers of several short laciniate or fimbriate scales, that of the 
ray-flowers of several or few short slender bristles, or none. [Named in honor of M. M. 
Galinsoga, superintendent of the Botanic Gardens at Madrid.] 
About 5 species, natives of tropical and warm temperate America, the following typical. 
