836 CARDUACEAE 



Achenes pubescent; bracts all narrow, the outer 

 not passing into the leaves; heads distinctly 

 peduncled. 34. Xylorrhiza. 



Achenes glabrous; outer bracts broad, foliaceous, 

 passing into the leaves; heads subsessile. 



35. Herrickl\. 

 Bracts not acuminate, or if long-attenuate with soft 



tips. 

 Pappus dilated at the apex; bracts narrow, more 



or less keeled. 36. Unaaiia. 



Pappus not dilated at the apex. 



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

 not at all foliaceous. 37. Eucephaltjs. 



Bracts usually narrow, when broad neither 



keeled nor with a prominent midvein. 

 Bracts more or less fohaceous 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 foliaceous, narrow and in 1-3 



series. 



Style-tips slender, usually twice as long 

 as the stigmatic portions; achenes 

 terete. 39. Oreostemma. 



Style-tips ovate or triangular and 

 acuminate-subulate; achenes flat. 



40. ASTERIGEROX, 



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

 taproot; bracts in many series, with herbaceous 

 spreading or reflexed tips; stigma-tips linear to fiU- 



form. 44. MACHAERANTHEEI.V. 



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



bristles or scales. 

 Inner pappus-bristles more or less thickened above; bracts 

 thin-coriaceous, without herbaceous tips, shorter than the 



disk. 41. DOEUNGERIA. 



Inner pap pus -bristles filiform, not thickened above; bracts 

 equalling the disk. 42. Ionactis. 



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

 aceous. 



Involucres turbinate; bracts well imbricate, in several series, scarious- 

 margined; disk-flowers white. 43. Leucelene. 



Involucres hemispherical or broader; bracts not scarious-margined, 

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



45. ERIGERON. 



II. Marginal pistillate flowers not ligulate, reduced to a fiUform or narrow short tube. 



47. Eschenbachia. 



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; hermaphrodite flowers few and sterile, their pappus with 

 clavate tips. 49. Berthelotl\. 



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



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



truncate. 

 Pistillate flowers all subtended by paleae and without pappus. 



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



hyaline appendage. 

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



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

 flowers barely concave or plane. 

 Paleae subtending the central flowers hyaline and deciduous; bracts 



of the involucres in several series. 50. Stylocline. 



Paleae subtending the central flowers coriaceous-herbaceous, ending in 

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

 paleaceous ones enclosing the marginal flowers. 



„ , , ^ , 51. Ancistrocarpiius. 



Heads globose; paleae subtending the pistillate flowers cucullate-saccate 

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

 porrect; paleae and pappus of the hermaphrodite flowers lacking. 



CO PsTTjOCARPUS 



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



appendage. 53. Dlaperia. 



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



and the central fertile hermap lirodite flowers not subtended by individual 



paleae, but the cluster surrounded by a ring of open scarious paleae, the 



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



