COMPOSITAE (COMPOSITE FAMILY) 489 



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

 more or less dichotomous cyme: brapts of the involucre in only abputS series, 

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

 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 nimierous erect stems from a woody base, 3-6 dm. 

 high: inflorescence cymose-paniculate;, heads short-pedimcled or sometimes 

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

 bracts with minute green tips: disk- and ray-flo^wers each 3-7,:. achenes 

 sericeous-pubescent. G. Euthamiae. {G. juncea Greene, 1. c. 56; G. divarieata 

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

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

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

 Almost throifghout the western United States. 



5. Gutierrezia microcephala Gray, PL 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, scaberulpus, 

 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. glornerella' a,nd G. fUifolia 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-puberulentj 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 hnear. 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 (3-4 dm.) . . . 1. G. subalpina. 

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

 Cauline leaves mostly oblong and sessile by a broad somewhat claspr 

 ing base; pappus-awns apparently smooth. ' ' 



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



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



Perennials. 



Hay^.wanting 5. G. fastigiata. 



Rays present. * 



Stems and leaves glabrous. 



None of the involucral bracts reflexed; pappus-awns barbellate 



above . . . . . . . . . , 6. G.'decuiubens. 



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. 



