FLOWERING PLANTS AND FERNS OF ARIZONA 187 



1 1. Stems scaly but scarcely bulbous at base: roots more or less tuberous- 

 thickened: leaves long and narrow, all basal or nearly so; flower.-. 

 in racemes: perianth segments separate or very nearly so; cap- 

 sules transversely rugose (12). 

 12. Raceme loose, elongate; perianth orange; anthers straight or near- 

 ly SO 3. AXTHERICUM. 



12. Raceme rather dense: perianth whitish with green veins; anthers 



becoming strongly incurved 4. Eremocrixum. 



11. Stems bulbous at base: roots not tuberous-thickened, or exceptionally 

 so in Hesperocallis (13). 



13. Plants caulescent, the stems more or less leafy (14). 



14. Bulbs tunicate, the coats thin and dry: leaf margins con- 

 spicuously undulate; flowers in scarious-bracted ra- 

 cemes 5. Hesperocallis. 



14. Bulbs with fleshy scales: leaf margins not undulate; flowers 

 solitary or few, terminal or subterminal (15). 

 15. Perianth segments 5 to 9 cm. long, bright yellow or orange 



red. usually with darker spots 11. Liliem. 



15. Perianth segments not more than 2 cm. long, dull yellow, veined 



and mottled with brownish purple 12. Fritillaria. 



13. Plants scapose, the leaves all basal: flowers in umbels, these sub- 

 tended by scarious bracts, or the flower solitary (16). 

 16. Perianth segments separate to the base or nearly so, pink or 

 whitish (17). 

 17. Ovules 2 in each cell of the ovary: seeds 1 or 2 in each cell; 

 plants with an odor of onions 6. Allium. 



17. Ovules several and seeds usually more than 2 in each cell; 



plant without odor of onions 7. Xothoscordum. 



16. Perianth segments united below into a funnelform tube (18). 



18. Filaments partly united into a tube, this with toothlike lobes 



between the anthers 9. Axdrostephium. 



18. Filaments not united into a tube (19). 



19. Umbels several- to many-flowered: perianth funnelform or 

 funnelform-campanulate; stigma small, capitate. 



8. Brodiaea. 

 19. Umbels 2- or 3-flowered, or the flower solitary: perianth 

 salverform: stigma large, somewhat funnelform. 



10. MlLLA. 



1. ZYGADENUS. Deathcamas 



Plants glabrous; flowering stems from bulbs, subscapose; leaves 

 narrow, grasslike; flowers in racemes or narrow panicles; perianth 

 segments each with a gland near the base, separate or united below; 

 styles 3, separate; ovary superior or partly inferior; fruit a 3-lobed 

 capsule. 



These plants are poisonous (Z. elegans perhaps only slightly so) and 

 sometimes cause heavy loss of sheep in spring and early summer when 

 other forage is scarce. Cattle and horses seldom eat deathcamas. 

 The toxic principle (zygadenin?) is found in all parts of the plant, 

 even in the seeds. 



Key to the species 



1. Perianth segments not more than 5 mm. long, pale yellow, abruptly contracted 

 into the claw and often subcordate at base, the eland- obovatewith the 

 upper margin not sharply defined; stamens much exserted; ovary su- 

 perior 1. Z. paniculate-. 



1. Perianth segments not less (commonly more) than 5 mm. long, not abruptly 

 contracted, more or less cuneate at base, the glands obcordate with a 

 sharply defined upper margin; stamens not or only moderately exserted; 

 ovary partly inferior (2 . 

 2. Branches of the inflorescence erect or ascending; pedicels commonly ascend- 

 ing, seldom decurved: perianth yellowish white . 2. Z. ELEGANS. 

 2. Branches of the inflorescence spreading: pedicels divergent, often decurved: 

 perianth greenish white, sometimes tinged with purple. 



3. Z. VIRES' 



