THISTLE FAMILY 233 



8. AMPHIPAPPUS T. & G. l. A. Fremontii. 



9. GRINDELIA Willd. Gum-plant, Resin-wbbd. 



Involucres not viscid. 1. G. platylepis. 



Involucres more or less viscid. 



Leaves all entire, the basal ones 3-4 dm. long; bracts narrowly Unear-lanceolate, the 



outer nearly filiform, rather thin. 2. G. oregana. 



Leaves, at least the basal ones, more or less dentate, the latter less than 2 dm. long; 

 bracts lanceolate, with thick, rather fleshy tips. 

 Heads radiate. 



Pappus-awns apparently smooth; barbules seen only under a compound micro- 

 scope. 

 Tips of the outer bracts spreading, none reflexed. 



Stem-leaves serrate. 3. G. decumbens. 



Stem-leaves laciniate. 4. G. laciniata. 



Tips of the bracts SQuarrose, those of the outer ones strongly reflexed. 

 Stem-leaves oval, ovate, or ovate-oblong with a broad base. 



Leaves bluish green, spinulose-dentate; heads very broad and flat, 

 its bracts broad and even the squarrose tips flattened. 



5. G. texana. 

 Leaves yellowish green, merely dentate; heads hemispherical, its 

 ' bracts narrow and with terete squarrose tips. 6. G. squarrosa. 

 Stem-leaves oblanceolate, rarely oblong. 



Pappus-awns scarcely longer than the achenes, curved and twisted. 

 Squarrose tips of the bracts short; leaves subentire. 



7, G. integerrima. 

 Squarrose tips of the bracts long and slender; leaves serrate, with 

 spreading teeth. 8. G. Brownii. 



Pairous-awns decidedly longer than the achenes, straight. 

 Leaves all finely serrate, dentate or subentire. 



Leaves finely and closely serrate. 9. G. serrulata. 



Leaves rather remotely dentate or subentire. 



10. G. perennis. 

 Leaves coarsely toothed, the basal ones sublaclniate. 



11. G. subincisa. 

 Pappus-bristles distinctly barbellate; barbiiles distinctly seen with a common 



pocket-lens. ^ 



Stems tall, 4-8 dm. high, usually solitary; stem-leaves broadly oblong or 

 obovate; bracts broad, only the outer ones squarrose-reflexed. 



12. G. erecia. 

 Stems low, about 3 dm. high, usually several from the base; stem-leaves 



oblanceolate or oblong; all bracts squarrose. 

 Heads discoid. 



Stem-leaves oval or obovate. 

 Stem-leaves oblanceolate or oblong. 



Outer bracts strongly recurved, the inner not squarrose. 

 All bracts squarrose. 



Bracts long and loose, but not strongly recurved. 

 Bracts short, strongly recurved-curled. 



10 VANCLEVEA Greene. 



11. ACAMPTOPAPPUS A. Gray. 



12. CHRYSOPSIS Nutt. Golden Aster. 

 Heads radiate. 



Involucres strigose. 



Heads sessile or subsessile, subtended by foliage-leaves. 



Leaves narrowly linear-oblanceolate, hirsute. 1. C. angusiifolia. 



Leaves oblanceolate, obovate, elliptic, or lanceolate, strigose at least when 

 young, except in C. imbricata. 

 Plant about 1 dm. high or less; heads usually soUtary. 

 Involucres 5-8 mm. broad; leaves less than 1 cm. long. 



2. C. caespitosa. 

 Involucre-s 10-12 mm. broad ; leaves 2-3 cm. long. 3. C. alpicola. 

 Plant 2-6 dm. high; heads corymbose. 



Leaves oblong or lanceolate, decidedly acute, those subtending the 



heads narrowly linear. 4. C. foliosa. 



Leaves oblanceolate or obovate, those of the inflorescence elliptic or 

 oval. 

 Disk of the heads about IS mm. broad; leaves strigose. 



Inner bracts with subulate, usually brownish and spreading tips. 



5. C. caudata. 

 Inner bracts merely acute. 6. C. amplifoHa. 



Disk of the heads 10-12 mm. broad ; leaves hirsutulous. 



7. C. imbricata. 

 Heads peduncled, naked or rarely subtended by one small leaf. 



Plant less than 1 dm. high; heads solitarj' at the ends of the branches. 



8. C. depressa. 

 Plant 3-3 dm. high; heads more or less corymbose. 



