83G CARDUACEAE 



Achenes pubescent; bracts all narrow, the outer 

 not passing into the leaves; heads distinct Is- 

 peduncled. 34. Xyujrrhiza. 



Achenes glabrous; outer bracts broad, foliaceous, 

 passing into the leaves; heads subsessile. 

 35. Herricki.\. 

 Bracts not acuminate, or if long-attenuate svith soft 

 tips. 

 Papi^us dilated at the apex; bracts narrow, more 



or less keeled. 36. Unaml\. 



Pappus not dilated at the apex. 



Bracts broad, with a distinct keel or mid-vein, 



not at all foliaceous. 37. Bucephalus. 

 Bracts usually narrow, when broad neither 

 keeled nor with a prominent midvein. 

 Bracts more or less foUaceous or foliaceous- 

 tipped, usually in several series; heads 

 usually several, racemose or paniculate; 

 stigma-tips lanceolate to subulate, shorter 

 than the stigmatic portion. 

 38. Aster. 

 • Bracts not fohaceous, narrow and in 1-3 



series." 

 Style-tips slender, usually twice as long 

 as the stigmatic portions; achenes 

 terete. 39. Oreostenevl^.. 



Style-tips ovate or triangular and 

 acuminate-subulate; achenes flat. 

 40. Asterigerox. 

 Annuals or biennials, or if short-hved perennials, with a 

 taproot; bracts in many series, ^vith herbaceous 

 spreading or refle.xed tips; stigma-tips linear to flU- 

 form. 44. Machaeraxthera. 



Pappus double, the inner of capillary bristles, the outer of short 

 bristles or scales. 

 Inner pappus-bristles more or less thickened above; bracts 

 tliin-coriaceous, without herbaceous tips, shorter than the 

 disk. 41. Doelixgeri-\.. 



Inner pappus-bristles filiform, not thickened above; bracts 

 equalling the disk. 42. Iox.\CTis. 



Style-tips triangular or ovate, obtuse or rarely acutish; bracts not foli- 

 aceous. 

 Involucres tm-binate; bracts well imbricate, in several series, scarious- 



margined ; disk-flowers white. 43. Leucelexe. 



Involucres hemispherical or broader; bracts not scarious-margined, 

 in 1-3 series; disk-corollas yellow, rarely ochroleucous. 



4.5. Erigerox. 

 II. Marginal pistUlate flowers not Ugulate, reduced to a fiUform or narrow short tube. 



47. Eschexbachia. 



B. Heads unisexual, dioecious, discoid; pappus of the staminate flowers with clavate tips. 



48. Baccharis. 

 Tribe 4. GNAPHALIEAE. 



Shrubs; bracts coriaceous; receptacle naked; pistillate flowers numerous; corolla reduced 

 to a short slender tube; hermaphi-odite flowers few and sterile, their pappus with 

 clavate tips. 49. Berthelotia. 



Herbs, if at aU shrubby only at the base; bracts more or less scarious. 



Receptacle chaffy; style or style-branches of the hermaphrodite sterile flowers not 

 trimcate. 

 Pistillate flowers all subtended by paleae and without pappus. 



Paleae in fruit enclosing the achenes and falling off with them, tipped with a 



hyaUne appendage. 



Heads ovoid; paleae subtending the pistillate flowers boat-shaped, with 



erect conspicuous hyaline tips, those of the 4-5 hermaphrodite 



flowers barely concave or plane. 



Paleae snbtending the central flowers hyaline and deciduous; bracts 



of the involucres in several series. 50. Styloclixe. 



Paleae subtending the central flowers coriaceous-herbaceous, ending in 

 a hooked spine, persistent; bracts of tiie involucres none beside the 

 paleaceous ones enclosing the marginal flowers. 



51. AXCISTROCARPHUS. 



Heads globose; paleae subtending the pistillate flowei"s cucullate-saccate 

 and utricular, the apex introrse and the ovate appendage inflexed or 

 porrect; paleae and pappus of the herniaphrodite flowers lacking. 



52. PSILOCARPUS. 



Paleae in fruit open and merely subtending the achenes, without a hyaline 



appendage. 53. Diaperia. 



PistUlate flowers of two kinds, the outer with, the inner without pappus, the latter 



and the central fertile hermaplirodite flowers not subtended by individual 



paleae, but the cluster siurounded by a rmg of open scarious paleae, the 



outer subtended by boat-shaped ones. 54. Oglifa. 



