266 CARDUACEAE 



Leaf-blades neither triangrilar nor cordate. 



Plant tall, 5-15 dm. high; heads numerous: plants with root- 

 stocks. V. Serrae. 

 Plant low, 2-4 dm. high: heads few. 



Heads radiate. XVI. Cr.vsscli. 



Heads discoid. XVII. R.\pifolii. 



Leaves pinnatifid. VI. Eremophili. 



Leaves or their divisions linear-flUform : plants usually suffruticose at the 

 base. VII. Loxgilobi. 



Plants with the stem-leaves more or less reduced upwards. 

 Rootstock well developed, horizontal or ascending, woody. 

 Stem leafy, more than 2 dm. lugh. 



Heads campanulate, rarely solitary. 



Stem stout: rootstock not cespitose : leaves caUous-denticulate or 

 salient ly dentate. 

 Heads di.scoid; leaves saUently dentate. 



XVII. Rapifolii. 

 Heads radiate: leaves callous-denticulate. 



Leaves glabrous. VIII. GL-\ucescextes. 



Leaves tomentose. IX. FoiJosi. 



Stem slender: rootstock usually more or less cespitose: leaves 

 neither caUoiis-denticulate, nor saliently and closely den- 

 tate: stem-leaves in the larger forms usually pinnatifid. 

 Basal lea^'es entire, more or less wliite-tomentose. 



X. Cani. 

 Basal leaves, at least most of them, toothed or pinnatifid. 

 Leaves and stem more or less floccose, tardily becoming 



glabrate. XI. Tomentosi. 



Leaves and stem glabrous or slightly floccose when young. 



XII Aurei. 

 Heads turbinate, solitary. XIII. Subnudi. 



Stem subscapose, less than 2 dm. high. XIV. Axdicol.\e. 



Rootstock very short, erect, of short duration, ■with numerous fleshy-fibrous 

 roots; leaves dentate or entire. 

 Tall bog-plants, 5-15 dm. high; basal leaves long-petioled 



XV. Hydrophili. 

 Meadow or wood-plants, 2-5 dm. high; basal leaves comparatively 

 short -petioled. 

 Leaves sharply and densely dentate. XVI. Cr.\ssuli. 



Leaves entire-margined or denticulate, seldom sinuate-dentate. 



XVIII. INTEGERRIMI 



Annuals 



Plant branched, more or less viscid: heads discoid, or with minute rays. 



XX. VULG.\RES 



Plant simple, more or less floccose: heads radiate. XXI. Palustres. 



I. PCDICI. 



Heads 12-20 mm. high, broadly campanulate. 



Auricles of the upper leaves small and entire: midvein of the leaves long-\-illous. 



1. S. accidens. 

 Aiu-icles of the upper leaves large and usually toothed ; midvein of the leaves not con- 

 spicuously villoas. 2. S. chlnranthus. 

 Heads 8-10 mm. high, narrowly campanulate. 3. S. pudicus. 



II. AlIPLECTEXTES. 



stem 2 dm. or more high, leafy; leaves acute. 



Stem-leaves with clasping bases; stem high, slightly floccose when young. 



4. S. amplectens. 

 Stem-leaves not clasping, iisually short-petioled. 5. S. pagosanus. 



Stem less than 2 dm. high. 



Rootstock hard, scaly at the top: upper stem-leaves sessile. 6. S. seridophyllus. 

 Rootstock fleshy, not scaly; stem-leaves usually petioled. 

 Basal leaves gradually tapering into the petioles. 



Plant glabrous or nearly so; leaves dentate; bracts oblong. 



7. S. Holmii. 

 Plant arachnoid-floccose; leaves pinnatifid; bracts narrowly lanceolate. 



8. S. taraiacoides. 

 Basal leaves abruptly contracted into the petioles. 9. S. SoldancUa. 



III. Occidentales. 



Plant 2-3 dm. high; stem-leaves obovate or oblong, clasping. 



Plant very leafy; involucres 10-15 mm. broad, short-peduncled or subsessile: achenes 



strigose. " 10. S. carlhamoides. 



Plant less leafv; involucres about 10 mm. broad, long-peduncled; achenes glabrous. 



11. S blitoides. 

 Plant about 1 dm. high: stem-leaves spatulate or obovate. scarcely clasping. 



Leaves obovate-spatulate; plant glabrous: achenes puberulent. 



12. S. Fremontii. 

 Leaves oval, spinulose-dentate; leaf-margins scaberulous; surfaces with a few hairs; 



achenes glabrous. 13. S. inrenustus. 



