FLOWERING PLANTS AND FERNS OF ARIZONA 269 



9. Leaf blades rounded-triangular or triangular-subhastate, entire 

 or inconspicuously repand-dentate; fruiting bracts obovate- 

 cuneate or semiorbicular, more or less truncate at apex, 

 laciniate, not strongly 3-nerved, usually conspicuously 



long-crested on the faces 5. A. argentea. 



Stems woody, at least near the base; plants mostly dioecious (10). 

 10. Fruits conspicuously 4-winged, the wings much broader than the body 

 of the fruit and extending to its base; plants shrubby; glomerules of 

 flowers mostly aggregated in leafy or nearly naked panicles of spikes 

 terminating the branches; leaf blades with entire margins, linear, oblong- 

 lanceolate, or spatulate (11). 

 11. Leaf blades commonly less than 3 mm. wide; fruiting bracts 4 to 8 

 mm. long, with free tips commonly much surpassing the wings, the 

 latter coarsely dentate to laciniate; herbage whitish. 



18. A. LINEARIS. 



11. Leaf blades commonly more than 3 mm. wide; fruiting bracts 6 to 20 



mm. long; herbage grayish or yellowish green (12). 



12. Blades usually broadest above the middle and less than 1 cm. wide; 



free tips of the fruiting bracts commonly not surpassing the 



wings; shrub 0.4 to 1.5 m. high 19. A. canescens. 



12. Blades usually broadest at the middle and 1 cm. wide or wider; free 

 tips of the fruiting bracts commonly surpassing the wings; 



undershrub less than 0.4 m. high 20. A. garrettii. 



10. Fruits not 4-winged (13). 



13. Bracts of the fruits with entire to denticulate margins, rounded-deltoid, 

 orbicular, or reniform, the faces smooth (14). 

 14. Leaf blades deeply and rather sharply dentate or laciniate; plant not 

 spinescent; foliage silvery white; fruiting bracts separate, thin, 



strongly compressed, entire 15. A. hymenelytra. 



14. Leaf blades sometimes subhastate, the margins otherwise entire; 

 plants commonly spinescent, the ends of the branches becoming 

 indurate and sharp pointed (15). 

 15. Glomerules of flowers in slender, dense or interrupted, elongate, 

 often drooping spikes commonly aggregated in large open 

 terminal panicles, these leafy or nearly naked toward apex; 

 fruiting bracts not more than 6 mm. long, sometimes united up 

 to the middle, usually crenulate; leaf blades oblong to deltoid- 

 ovate, often subhastate; plants commonly tall, 1 to 3 m. high. 



"16. A. LENTIFORM1S. 



15. Glomerules of flowers small and dense, axillary or in short leafy 

 spikes, the pistillate flowers sometimes solitary; fruiting bracts 

 5 to 15 mm. long, united only at base, entire or denticulate; 

 leaf blades oval, ovate, obovate, or suborbicular, never sub- 

 hastate-deltoid; plant usually rounded and compact, less than 



1 m. high 17. A. confertifolia. 



13. Bracts of the fruits normally with dentate to laciniate margins, the 

 faces often tuberculate or crested (16). 

 16. Leaf blades with sinuate or sinuate-dentate (seldom entire) margins; 

 fruiting bracts pedicellate, 6 to 14 mm. long, with laciniate mar- 

 gins and the faces bearing long hornlike processes; plant suffru- 



tescent; foliage usually silvery white 10. A. acanthocarpa. 



16. Leaf blades with entire margins; fruiting bracts not more than 6 mm. 



long (17). 



17. Plant an intricately and rigidly branched shrub; stems 0.5 to 2 m. 



high; leaf blades mostly less than 1 cm. long; fruiting bracts 



normally deeply dentate on nearly the whole margin, including 



the truncate apex 14. A. poltcarpa. 



17. Plants suffrutescent; stems not more than 0.5 m. high; leaf blades 

 seldom less than 1 cm. long (18). 

 18. Apical portion of the fruiting bracts broadly deltoid, with mar- 

 gins entire or denticulate 13. A. CORRUGATA. 



18. Apical portion of the fruiting bracts truncate and dentate, or 

 entire and beaklike, the faces bearing a few short blunt ap- 

 pendages or nearly smooth (19). 

 19. Bracts united only at the truncate or subcordate base; herb- 

 age silvery 11. A. obovata. 



19. Bracts united above the broadly cuneate base; herbage 

 yellowish 12. A. jonesil 



