1294 CAEDUACEAE 



elliptic or spatulate at the base of the stem to oblong or linear above, those of the lower 

 leaves sharply but shallowly and remotely serrate : heads relatively short-peduncled : 

 bracts of the involucre ovate-lanceolate to lanceolate, 8-11 mm. long : ligules of the ray- 

 flowers yellow, 1.5-2 cm. long : disk purple or brown : achenes 1.5-2 mm. long : pappus- 

 bristles 4 times as long as the achene, slender-tipped. 



On dry prairies, Arkansas to Oklahoma and Texas. Spring to fall. 



6. Gaillardia pulch611a Foug. Annual, hirsute. Stems 1-3 dm. tall, diffusely 

 branched at the base : leaf -blades spatulate to oblong or linear, 2-10 cm. long, entire or 

 pinnatifid : involucral bracts lanceolate to linear-lanceolate. 1-1.5 cm. long, acuminate : 

 ligules of the ray-flowers conspicuous, 1-2.5 cm. long, yellow beyond the red-purple base : 

 disk-corollas with subulate acute lobes sometimes ending in apiculate or bristle-like cusps : 

 achenes obconic, 2 mm. long : pappus-scales with the slender tips longer than the broad 

 bodies. 



On plains and prairies, Kansas to Louisiana and Arizona. Spring and summer. 



7. Gaillardia amblyodon Gay. Annual, hirsute or hispid. Stems 2-6 dm. tall, 

 simple or sparingly branched : leaf-blades spatulate to oblong or nearly linear, 2-7 cm. 

 long, entire or nearly so, sessile by the slightly auricled base : involucral bracts lanceo- 

 late to linear-lanceolate, acuminate, hispid : ligules of the ray-flowers brownish red or 

 maroon, 1.5-2.5 cm. long, oblong-cuneate : achenes glabrous or nearly so above, not over- 

 topped by the basal hairs : pappus-scales various, those of the ray awiiless. 



On prairies. Texas. Summer and fall. 



8. Gaillardia pinnatifida Torr. Perennial, cinereous-pubescent. Stems solitary or 

 tufted, 1-4 dm. tall, simple above : leaves mainly basal, or on the lower part of the scape- 

 like stems ; blades various, linear to spatulate, 4-12 cm. long, repand-pinnatifid to pinnatihd, 

 the segments linear or nearly so : involucral bracts narrowly linear to linear-lanceolate, 

 7-9 mm. long : ligules of the ray-flowers yellow, 1.5-2 cm. long or much reduced : achenes 

 with long hairs all over : pappus-scales lanceolate or oblong, prolonged into slender tips. 



On plains, Colorado to Texas and Arizona. Summer and fall. 



127. BOEBERA Willd. 



Annual or perennial caulescent strong-scented herbs. Leaves alternate or opposite : 

 blades commonly parted or dissected. Heads radiate, not showy. Involucres often nar- 

 row : bracts in 1 series, united at the bae, usually accompanied by several small scales. 

 Receptacle flat or nearly so, often with hairs or short bristles. Ray-flowers pistillate, fruit- 

 producing : ligules short. Disk-flowers perfect : corollas tubular. Anthers entire or mi- 

 nutely 2-toothed at the base. Stigmas of the disk flowers somewhat elongated, hirsute, 

 occasionally abruptly apiculate. Achenes broadened upward, 3-5-angled. Pappus of 10 

 or more partially united scales, the free portions divided into stiff slender segments. 

 [Dysodia Lag., notCav.] 



1. Boebera papposa (Vent.) Rydb. Annual, ill-scented, more or less pubescent. 

 Stems 1-4 dm. tall, widely branched : leaves opposite ; blades 1-3 cm. long, once or twice 

 pinnately parted, the segments linear : heads short-peduncled : involucres 5-8 mm. high ; 

 bracts oblong or oblong-obovate, obtuse, greenish or purplish, scarious-margined : ligules 

 of the ray-flowers inconspicuous: achenes 3.5-4 mm. long, pubescent. [Dysodia chry- 

 santhemoides Lag.] 



In waste places and on roadsides, Minnesota to Ohio. Louisiana, Mexico and Arizona. Summer 

 and fall. Introduced eastward. 



128. THYMOFHYLLA Lag. 



Annual or perennial caulescent usually pleasant-scented herbs or shrubby plants, with 

 glandular-dotted foliage. Leaves alternate or opposite : blades entire or pinnately parted. 

 Heads radiate, heterogamous, often disposed in corymbs. Involucres campanulate : bracts 

 mostly united into a cup usually accompanied by several scales at its base. Receptacle 

 naked or merely fimbrillate. Ray-flowers pistil! ate, fruit-producing. Disk-flowers perfect, 

 fruit-producing : corollas often yellow. Anthers truncate or obtuse at the base. Stigmas 

 obtuse or truncate, or sometimes minutely apiculate. Achenes terete or nearly so. striate. 

 Pappus of several or many truncate or 1-5-awn-tipped scales. [Hymenatherum Cass.] 



