sometimes fleshy or with prickly margins, occasionally fibrous, the venation mostly 

 parallel but also reticulate-parallel in some genera; inflorescence various; flowers 

 bisexual or rarely unisexual (with the plants mostly dioecious), regular (in ours); 

 perianth often large and showy, in 2 series of 3 segments each, very rarely fewer 

 or more, usually undifferentiated into corolla and calyx, the segments imbricate 

 or the outer series valvate, sometimes connate into a tube; stamens 6, rarely fewer 

 or more, hypogynous or adnate to the perianth; filaments distinct or connate; 

 anthers 2-celled, extrorse or antrorse, versatile or basifixed, dehiscing usually by 

 vertical slits; pistil 1; ovary usually 3-celled; styles 1 or 3, sometimes divided or 

 trifid; fruit a septicidal or loculicidal capsule or a berry; seeds various. 



More than 4,000 species in about 250 genera throughout the world. Many are 

 of great economic and horticultural importance. 



1. Flowers or inflorescences in the axils of alternate stem leaves (2) 



1. Flowers or inflorescences terminal (3) 



2(1). Plant erect, without tendrils; leaves cordate-clasping at base 



10. Streptopus 



2. Plant viny, with tendrils; leaves petiolate 13. Smilax 



3(1). Flowers usually 1 or 2 (4) 



3. Flowers more than 5, variously arranged (5) 



4(3). Leaves in a terminal whorl of 3; perianth purple, yellowish-green, pink or 

 white 1 1. Trillium 



4. Leaves in several whorls on the stem; perianth pale lemon-yellow and minutely 



dotted 7. Lilium 



5(3). Flowers in umbels 6. Allium 



5. Flowers in racemes, corymbs or panicles (6) 



6(5). Floral segments united except at apex into a tubular or campanulate 

 perianth 12. Aletris 



6. Floral segments distinct or slightly united only at base, the perianth lobes 



then much longer than the tube (7) 



7(6). Style single, sometimes cleft at tip (8) 



7. Styles 3 (10) 



8(7). Leaves ovate to lanceolate, alternate on the stem; flowers white; fruit a 

 berry 9. Smilaciiia 



8. Leaves linear, grasslike, in a basal tuft; flowers yellow to orange or blue; 



fruit a capsule (9) 



9(8). Flowers blue or purplish-blue; filaments filiform 8. Camassia 



9. Flowers yellow to orange; filaments somewhat flattened below the middle 



3. Schoenolirion 



10(7). Anthers ovate-cordate, 2-celled; leaves 2-ranked and equitant; inflores- 

 cence glutinous 1 . Tofieldia 



10. Anthers peltate or reniform, with confluent cells; leaves and inflorescence not 



as above (11) 



11(10). Axis of inflorescence glabrous; seeds not flat, narrowly winged or wing- 

 less 2. Zigadenus 



1 1. Axis of inflorescence pubescent; seeds flat, broadly winged (12) 



12(11). Perianth segments with narrow claws and conspicuous glands (nectaries) 

 at base of blade, free from ovary 4. Mclanthium 



12. Perianth segments clawless and glandless, usually adnate to base of ovary 



5. Veratrum 



648 



