THISTLE FAMILY 249 



Involucre conspicuously hirsute as well as glandular; stem low, usually 



with a single head. 59. E. rubicundus. 



Involucre slightly if at all hirsute; stem 3 dm. high or more, usually with 

 more than one head. fiO. E. eximius. 



Bracts lance-subulate; ligules white. 43. E. Coulteri. 



Stem scarcely hairy, decidedly glandular above. 61. E. Smithii. 



Leaves and stem more or less pubescent. 



Involucres about 18 mm. broad; plant conspicuously long-hairy. 



62. E. formosissimus ■ 

 Involucres about 15 mm. broad; plant less conspicuously hairy, more glandular. 



63. E. viscidus. 

 XI. Philadelphici. 



Basal leaves crenate or dentate, with broad rounded or ovate teeth; UOTer leaves lanceo- 

 late, acute; rays white or piiik. 64. E. philadelphicus. 



Basal leaves dentate, with sharp, triangular, saUent teeth; upper stem-leaves triangular- 

 lanceolate, acuminate; rays rose-colored or purple. 65. E. purpureus. 



XII. ASPERI. 



Pubescence short, usually not dense. 



Pubescence appressed or rarely spreading; hairs not with pustulate bases. 



Heads smaU; disk 1 cm. or less wide; Ugules white; basal leaves hnear-oblanceolate, 



entire. ~ 66. E. asper. 



Heads larger; disk 1-1. S cm. wide; ligules blue or purple; basal leaves usually more 

 or less toothed, oblanceolate. 67. E. oblanceolatus. 



Pubescence spreading; hairs with pustxilate bases; basal leaves narrowly oblanceolate; 

 ligules white or rarely pale rose. 68. B. consobrinus. 



Pubescence long, dense, spreading or reflexed. 69. E. Drummondii. 



XIII. Eamosi. 

 One species. 70. E. ramosus. 



XIV. Beludiastra. 



One species. 71. E. Bellidiastrum. 



XV. DlVERGENTES. 



stem simple below; rays usually white. 72. E. Wooloni. 



Stem branched at the base; rays usually purpUsh. 73. E. divergens. 



XVI. Flageli,ahes. 



Leaves and stems appressed-hairy. ^ 74. E. flagellaris. 



Leaves and stem densely short-pubescent with spreading hairs. 



Basal leaves oblanceolate, entire, or 3-lobed at the apex ; loaves of the stolons linear ; 



plant gray. ■ 75. B. commixtus. 



Basal leaves obovate-spatulate, entire, or with several lateral lobes or teeth; leaves 

 of the stolons oblanceolate ; plant greener. 76. E. nudiflorus. 



XVII. CANI. 

 Disk of the heads fully 1 cm. high and about 1.5 cm. wide; basal leaves spatulate, obtuse. 



Leaves canescent. 77. E. Wyomingia. 



Leaves silvery white. 78. E. argentatus. 



Disk of the heads 7-8 mm. high and about 1 cm. wide; basal leaves oblanceolate, mostly 



acutish. 79. E. canus. 



XVIII. Caespitosi. 

 Stem leafy; stem-leaves almost as broad as the basal ones. 



Lower leaves narrowly linear-oblanceolate ; upper leaves narrowly linear; all acute 



and coarsely hairy;. rays usually Ulac or purpUsh. 80. E. corymbosus. 



Lower leaves oblanceolate or linear-spatulate, usually obtusish; stem-leaves hnear 

 or oblong; all densely canescent; rays usually white. 

 Stem erect, about 3 dm. high, usually with several heads ; stem-leaves linear. 



81. E. subcanescens. 

 Stem decumbent at the base, 1-2 dm. high, with 1-3 (seldom more) heads ; stem- 

 leaves oblong. 

 Plant not conspicuously glandular. 82. E. caespilosus. 



Plant conspicuously glandular. 83. E. nauseosus. 



Stem more or less naked above, decumbent at the base; stem-leaves at least the upper 

 ones reduced. 

 Stems about 2 dm. high; disk 10-12 mm. high and about 15 mm. wide. 



84. E. nevadensis. 

 Stems about 1 dm. high; disks about 6 mm. high and less than 1 cm. wide. 



83. E. Eaionii. 



XIX. Ai3PEKUGINEI. 



Leaves with a spreading rough pubescence. 86. E. asperugineus. 



Leaves strictly appressed-cinereous. 



Disk 10-15 ram. wide; leaves finely and densely hairy; involucral bracts strigose. 



87. E. Tweedyi. 

 Disk 5-10 mm. wide; leaves sparingly and coarsely hairy; involucral bracts hirsute 

 and glandular-puberulent. 88. B. tener. 



XX. Abenarioides. 



One species. 89. E. arenarioides. 



XXI. Laetevirentes. 

 Stems 1.5-2 dm. high, leafy. 



Ligules blue or purple, scarcely more than 1 mm. wide. 90. E. laetevirens- 



