COMPOSITAE (COMPOSITE FAMILY) 489 



rescence of large and rather broadly turbinate involucres formed into an open 

 more or less dichotomous cyme: bracts of the involucre in only about 3 series, 

 with thick, obtuse, green tips: rays 5 or 6, disk-flowers 8 or 10: pappus-scales 

 in the disk-flowers 8-12, very narrow and acute, those of the disk (as is usual 

 in the genus) less than half as long. (G. scoparia Rydb. 1. c.) Common on 

 the plains and in the foothills; Montana to New Mexico and westward. 



4. Gutierrezia Sarothrae (Pursh) B. & R. Trans. N. Y. Acad. 7: 10. 

 1887. Bushy plant with numerous erect stems from a woody base, 3-6 dm. 

 high: inflorescence cymose-paniculate; heads short-peduncled or sometimes 

 in terminal glomerules of 3-5: involucre clavate-oblong, 3 or 4 mm. high; 

 bracts with minute green tips: disk- and ray-flowers each 3-7: achenes 

 sericeous-pubescent. G. Euthamiae. (G. juncea Greene, 1. c. 56; G. divaricata 

 Nutt.; G. myriacephala A. Nels. Bot. Gaz. 37: 264. 1904. Numbers 2 and 3 

 above are closely allied to this and are distinguished from it with difficulty. 

 It were better perhaps to consider them forms of this as did Dr. Gray.) 

 Almost throughout the western United States. 



5. Gutierrezia microcephala Gray, PI. Fendl. 74: 1848. Tufted stems 

 3-6 dm. high, slender, fastigiately corymbose, the branches of the season 

 striate, glabrous or hirtellous: leaves narrowly linear, ascending, scaberulous, 

 punctate, the ultimate twigs of the inflorescence and the involucres glutinous; 

 the latter mostly sessile in glomerules of 3-5, nearly cylindric, usually with 

 only 1-2 each of ray- and disk-flowers; the bracts few, obtuse or acute, scarcely 

 green-tipped. (G. glomerella and G. filifolia Greene, 1. c. 54 & 55.) Colorado 

 to Texas and westward. 



7. GRINDELIA Willd. GUM PLANT 



Coarse biennials or perennials. Basal leaves commonly petioled; the cau- 

 line mostly sessile, either narrowed petiole-like or clasping by a broad base. 

 Herbage glabrous or scabro-puberulent, balsamic-viscid and often punctate. 

 Heads gummy, medium to large, in panicles or cymes, or rarely solitary; disk 

 and rays yellow, or rarely the latter wanting. Involucre campanulate or 

 hemispheric; the bracts many-ranked, firm-herbaceous, often with attenuate, 

 squarrose points. Style-appendages lanceolate or linear. Achenes short, 

 truncate, compressed or turgid, glabrous. Pappus of 2-8 awns or small 

 scales, very readily deciduous. 



Biennials strictly. 



Cauline leaves mostly oblanceolate and narrowed to a petiole-like 



base; pappus bristles distinctly barbellate. 

 Stems usually 2 or more from the crown, low (2-4 dm.) . . . 1. G. subalpina. 



Stems usually solitary, tall (4-8 dm.) 2. G. erecta. 



Cauline leaves mostly oblong and sessile by a broad somewhat clasp- 

 ing base; pappus-awns apparently smooth. 



Involucral bracts broad with flattened tips 3. G. texana. 



Inyolucral bracts narrow, with terete tips . . . . . 4. G. squarrosa. 

 Perennials. 



Rays wanting 5. G. fastigiata. 



Rays present. 



Stems and leaves glabrous. 



None of the involucral bracts reflexed; pappus-awns barbellate 



above . . . . . . . . . . 6. G. decumbens. 



Some of the outer (at least) involucral bracts reflexed; pappus- 

 awns apparently smooth. 

 Leaves evenly serrate or dentate . . . . . . 7. G. perennis. 



Leaves irregularly toothed or lacerate . . . . . 8. G. subincisa. 



Stems and leaves crisped-hairy or subscabrous . . . . 9. G. scabra. 



1. Grindelia subalpina Greene, Pitt. 3: 297. 1898. Biennial, usually 2- 

 several unequal stems from the crown, 2-4 dm. high, corymbose-panicled : 

 leaves mostly oblanceolate, those of the crown slender-petioled, more or less 

 toothed and incised, the teeth mucronate: heads depressed-globose; bracts of 

 the involucre numerous, with filiform, squarrose-spreading and more or less 

 reflexed tips, the whole very glutinous (before opening often filled with the 

 white gummy exudation) : rays numerous, the expanded head 3-5 cm. broad. 



