THISTLE FAMILY 845 



Michx. L. scariosa Auth., not L. Prairies: Wis. Mo. Kans. N.D. Plain. 

 Au-S. 



5. L. spicata (L.) Kuntze. Stem 3-18 dm. high, glabrous or nearly so; 

 leaves numerous, linear, obtuse, 5-30 cm. long, obscurely punctate, glabrous: 

 heads very numerous, campanulate, about 1 cm. high; spike 2-4 dm. long; bracts 

 oblong, scarious-margined at the apex; flowers purple, rarely white. L. kansana 

 Britton. Liatris spicata (L.) Willd. Moist soil: Mass. Fla. La. Colo. Plain. 

 Au-O. 



6. L. pycnostachya (Michx.) Kuntze. Stem more or less hirsute above, 

 6-15 dm. high, very leafy; leaves linear or lance-linear, attenuate at the apex, 

 often 3 dm. long; heads 3-6-flowered, 8-12 mm. long; bracts oblong, pubescent 

 and ciliate, purple-tinged; flowers purple. Liatris pycnostachya Michx. Prair- 

 ies: Wis. Ky La. Tex. S.D. Plain. Au-S. 



7. GUTIERREZIA Lag. BROWN-WEED. 



Annual or perennial herbs or shrubs, with glutinous foliage. Leaves alter- 

 nate, narrow, entire. Heads radiate, usually many, clustered in terminal corymbs. 

 Involucres campanulate, oblong, or clavate, few- or many-flowered, small; bracts 

 leathery, imbricate in few series. Ray-flowers few, pistillate, fertile. Disk- 

 flowers hermaphrodite, perfect, or the central ones sometimes sterile; corollas 

 yellow. Anthers obtuse at the base. Stigmas flattened; appendages narrow. 

 Achenes obovate or oblong, terete or 5-angled; pappus of many short scales or 

 that of the ray-flowers sometimes wanting. 



Disk- and ray-flowers in the head 4-7 each. 



Surface of the leaves marked with large dots, each bordered by a hyaline scale. 



1. G. lepidota. 

 Surface of the leaves not lepidote, either puberulent or glabrous. 



Axils of the leaves with fasciculate branches. 2. G. fasciculata. 



Axils of the leaves without fasciculate branches. 



Plant ligneous only at the short persistent caudex. 

 Leaves linear, usually 1.54 mm. wide. 

 , Involucres oblong-turbinate, over 5 mm. high; outer bracts lanceolate; 



stems 3-4 dm. high. 3. G: scoparia. 



Involucres campanulate, somewhat turbinate at the base, less than 5 

 mm. high; bracts ovate; stems 1-2 dm. high. 4. G. diver sifolia. 



Leaves linear -filiform, less than 1 mm. wide. 



Ligules of the rays nearly as long as the involucre. 5. G. filifolia. 



Ligules of the rays about half as long as the involucre. 



Heads usually peduncled and solitary at the ends of the branches. 



6. G. divaricata. 

 Heads usually subsessile in clusters of 3-4 at the ends of the branches. 



Plant low, 1-2 dm. high; branches green; leaves 1-2 cm. long. 



7. G. juncea. 

 Plants 2-5 dm. high; branches with straw-colored or gray bark; 



leaves 3-4 cm. long. 8. G. Sarothrae. 



Plant shrubby. 



Involucres elongate, clavate-turbinate, 2-3 mm. wide; bracts oblong. 



9. G. longifolia. 

 Involucres campanulate, only slightly turbinate at the base, 3^ mm. wide; 



outer bracts ovate or obovate. 10. G. linearis. 



Disk- and ray-flowers in the head only 1-2 each. 11. G. glomerella. 



1. G. lepidota Greene. Stem about 4.5 dm. high, glabrous; lower leaves 



yellow; pappus squamellae lanceolate, acute. Perhaps belonging to some other 

 genus. Plains: Grand Junction, Colo. Son. Au. 



2. G. fasciculata Greene. Stem shrubby below, 3-5 dm. high, sparingly 

 scaberulous; leaves few, widely spreading, linear; axillary fascicled branches 

 often bearing a single head; involucre oblong-clavate, 4 mm. high; bracts in 4 

 series, the outer with stout green tips; disk- and ray-flowers each 5, pale yellow; 

 achenes silky; pappus squamellae lanceolate. Valleys: Colo. Son. Au. 



3. G. scoparia Rydfj. Plant woody only at the base, about 3 dm. high; 

 branches numerous, puberulent, mostly simple up to the inflorescence; leaves 

 linear, 3-5 cm. long, 1-2 mm. wide, puberulent; inflorescence corymbiform; 



