262 CARDUACEAE 



Leavas linear-lanceolate, entire or short-lobed, thicker, sparingly Hoccose 

 above; involucre arachnoid. 29. A. arachnoidea. 



Heads very numerous in dense compound panicles (except in A. Lindleyana), 5-25- 

 flowered; involucre campanulate or ellipsoid. 

 Upper leaves lanceolate or oblanceolate, usually more than 4 mm. wide. 



Involucre 4 mm. high; leaves large, 5-15 cm. long, lanceolate or ovate-lanceo- 

 late in outline, with very few divisions, directed forward. 

 Lower leaves deeply divided into more or less falcate divisions. 



30. A. Hookeriana. 

 Lower leaves with shorter lobes or teeth directed forward. 



Heads nodding ha anthesis, 15-25-flowered; involucre rounded-cam- 



panulate. 31. A. Douglasiana. 



Heads erect in anthesis, 5-15-fiowered; involucre oblong or subcylindric. 



32. A. Herriotii. 

 Involucre 3 mm. liigh; leaves shorter; lobes of the lower leaves often spreading. 

 Leaves of a lanceolate type; involucre campanulate, usually less than 3 



mm. broad. 33. A. ludoticiana. 



Leaves of a cuneate tjije; involucre hemispheric, 3-4 mm. broad. 

 Leaves with 3-5 ovate teeth at the ape.x, dark green. 



34. A. cuneata. 

 Leaves with 3-7 lanceolate lobes, yellowish green. 



49. A. rhizomata. 

 Upper leaves linear or narrowly linear-oblanceolate, less than 4 mm. wide. 



Heads numerous, paniculate; leaves usually more than 5 cm. long; plant not 

 suffruticose at the base. 

 Inflorescence loose; branches long and heads scattered. 



Leaves entire, or the lower coarsely toothed or with short lanceolate 



lobes. 35. A. silvicnla. 



Leaves, at least some of them, with long narrow, alternate, salient, fal- 

 cate lobes. 36. A. falcata. 

 Inflorescence dense and narrow; branches short; heads crowded; stem- 

 leaves mostly pinnatifid. 

 Bracts and upper surface of the leaves nearly glabrous; lower surface 



minutely tomentulose. 37. .4. potens. 



Bracts and upper surface of the leaves floccose; lower surface white- 



tomentose. 38. A. Underu-oodii. 



Heads less numerous, in narrow spikes or spike-like panicles; leaves narrow, 



usually less than 5 cm. long, the lower toothed or rarely lobed towards 



the ape.x, the upper entire, linear or nearly so; plant suffruticose at the base. 



39. A. Lindleyana. 

 IX. Gnaphaloides. 

 Leaves all entire or the basal ones merely toothed. 



Involucre 3-4 mm. high, 2-3.5 mm. broad; heads less than 25-flowered. 



Corollas dark brown or purphsh; leaves usually less tomentose above, the lower 



serrate towards the apex. 40. A. gnaphaloides. 



CoroUas light brown or yellow; leaves equally white-tomentose on both sides. 

 Involucre 2-2.5 mm. "broad; leaves very narrow, linear or lance-Unear, acute. 



41. A. pabularis. 

 Involucre 2.5-3.5 mm. broad; leaves broader, if lance-linear, more or less 

 acuminate. 

 Upper leaves ovate to lanceolate, acute; heads densely crowded and usually 



erect. 42. A. Purshiana. 



Upper leaves lanceolate to lance-linear, acuminate; heads less crowded, 

 mostly spreading. (lintire-leaved forms of j 46. A. dirersifoUa. 



Involucre 4-5 mm. "high, 4-7 mm. bi'oad; heads 25-40-flowered (in A. longifoUa some- 

 times 20-25-flowered). 

 Heads nodding or spreading; leaves equally floccose on both sides, not revolute, 

 acute. 

 Heads nodding, rather long-peduncled on elongate racemiform branches; 



leaves linear. 43. A. pudica. 



Heads spreading, subsessile or short-peduncled on shorter branches; stem- 

 leaves lanceolate. 44. A. argophylla. 

 Heads erect, pedimcled; stem-leaves linear-lanceolate, caudate-attenuate, often 

 revolute-margined and greener above. 45. A. longifoUa. 

 Leaves, at least the lower ones, more or less lobed or divided. 

 Lower leaves with simple divisions. 



Lower leaves with long and narrow lobes. 



Involucre 3-4 mm. liigh, 3-4 mm. broad. 46. A. diversifolia. 



Involucre 4-5 mm. high, 5-7 mm. broad. 44. A. argophylla. 



Lower leaves with short and broad often salient lobes. 



Leaves 5-8 cm. long; involucre 4-5 mm. high and about as broad. 



47. .4. plaUjphylla. 

 Leaves 1-5 cm. long; involucre 3-4 mm. high, 2-3 mm. broad. 



Stem simple up to the inflorescence. 



Inflorescence dense and much branched; heads clustered. 



48. A. Brittonii. 

 Inflorescence lax, narrow, spike-hke, with short racemiform branches. 



49. A. rhizomata ^ 

 Stem conspicuously branched, the branches ending in small simple or 



branched racemes. 50. A. albula. 



Lower leaves and often the upper with narrow, again cleft or toothed, spreading divi- 

 sions. 



