836 CARDUACEAE 



Achenes pubescent: bracts all narrow, the outer 

 not passing into tlie leaves; heads distinctly 

 peduncled. 34. Xylorrhiza. 



Achenes glabrous; outer bracts broad, foliaceous, 

 passing into the leaves; heads subsessile. 

 35. Herricki.\. 

 Bracts not acuminate, or if long-attenuate with soft 

 tips. 

 Pappus dilated at the apex; bracts narrow, more 



or less keeled. 36. Un.^mia. 



Papi)iLs not dilated at the apex. 



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



not at aU foliaceous. 37. Eucephalus. 

 Bracts usually narrow, when broad neither 

 keeled nor with a prominent midvein. 

 Bracts more or less foUaceous or foUaceous- 

 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 foUaceous, narrow and in 1-3 

 series. 

 Stjle-tips slender, usually twice as long 

 as the stigmatic portions; achenes 

 terete. 39. Oreostemma. 



Style-tips ovate or triangular and 

 acimoinate-subulate ; achenes flat. 

 40. Asterigeron. 

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

 taproot; bracts in many series, with herbaceous 

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

 form. 44. Machaeranthera. 

 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 

 dl.sk. 41. Doelingeria. 

 Inner pappus-bristles filiform, not tliickened above; bracts 

 equalling the disk. 42. Ionactis. 

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

 aceous. 

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



margined ; disk-flowers wliite. 43. Leucelene. 



Involucres hemispherical or broader; bracts not scarious-margined, 

 in 1-3 series; disk-coroUas yellow, rarely ochroloiicous. 



45. KHHiEIidX. 



II. Marginal pistillate flowers not Ugulate, reduced to a filiform oi- narrow short tube. 



47. KstHENBACHIA. 



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



48. BACCH.'i.RIS. 



Tribe 4. GNAPHALIEAE. 



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

 to a short slender tube; hermaphrodite flowers few and sterile, their i)appus with 

 clavate tips. 49. Berthelotia. 



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



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

 truncate. 

 Pistillate flowers all siibtended by paleae and without pappus. 



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



hyaline appendage. 



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



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



flowers barely conca\c or i)laiic. 



Paleae subtending the ((iiiral flowers hyaline and deciduous; bracts 



of the involucres in several series. 50. STYLOCLINE. 



Paleae sulitciulinf^ tlK; central llowers coriaceous-lKirbaccous, ending in 

 a hooked sjiine, ])ersisi('nt : hrafts of the in\(>lucres none beside the 

 paleaceous ones enclosing the marginal llowc^rs. 



51. .\N'rrsTROrARPIIUS. 



Heads globose; paleae subtending the pistillate flowcu's eueuUatc-saccate 

 and utricular, the apex introrso and the ovate apI)e^(la^'e iailexed or 

 porrcct; paleae and pappus of the hermaplirodite flowers lackuig. 



52. PSILOCARPUS. 



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



appendage. 53. Diapekia. 



Pistillate flowers of two kinds, the outer with, the inner without i)appus, the latter 



and the central fertile hcrmaplii-odite 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. 



