xxviii 



7a. Flowers in globose heads which are arranged in spikes, the low- 

 est heads pistillate, the upper staminate; ovary 1-celled 



SPARGANIACEAE, p. 2. 



7b. Flowers in globose woolly heads terminating leafless unbranched 



stalks ERIOCAULACEAE, p. 9. 



7c. Flowers in a spike-like raceme; ovaries 3 6, separate or nearly 



so JUNCAGINACEAE, p. 3. 



7d. Flowers in heads or panicles, all perfect, not woolly, with one 



ovary 8. 



8a. Leaves less than 1 cm. wide, or none; divisions of the 

 perianth 6 JUNCACEAE, p. 10. 



8b. Leaves 2 cm. wide or more; petals 5 



2a, in UMBELLIFERAE, p. 80. 

 9a. Flowers regular, with all the petals of approximately the same 



size and shape 10. 

 Db. Flowers irregular, with the petals of each flower not of the same 



size or shape 22. 

 lOa. Ovaries 3 or more, separate or barely united with each other 



at the base 11. 



lOb. Ovary one in each flower 12. 



lla. Ovaries 3 6 in number; flowers in spikes or racemes; leaves 



linear JUNCAGINACEAE, p. 3. 



lib. Ovaries more than 6 ALISMACEAE, p. 3. 



12a. Flowers or flower-clusters lateral, axillary or apparently 



so 13. 

 12b. Flowers or flower-clusters terminal or on leafless stalks 



14. 

 13a. Leaves minute and scale-like; flowers greenish-yellow 



2a, in LILIACEAE, p. 10. 



13b. Leaves linear, grass-like 3b, in IRIDACEAE, p. 13. 



13c. Leaves lanceolate or broader, not gra^s-like or scale-like 



2b, in LILIACEAE, p. 10. 



14a. Divisions of the perianth 5 12 cm. long 15. 

 14b. Divisions of the perianth less than 5 cm. long 16. 

 15a. Flowers blue, or blue marked with yellow 



la, in IRIDACEAE, p. 15. 



15b. Flowers not blue 12a, in LILIACEAE, p. 11. 



16a. Flowers solitary 17. 



16b. Flowers 2 or more, in some kind of a cluster 18. 

 17a. Leaves 2, broadly heart-shape, basal, on long stalks 



Ib, in ARISTOLOCHIACEAE, p. 25. 



17b. Leaves not heart-shape 20, in LILIACEAE, p. 12. 



18a. Divisions of the perianth (4 to 6) all essentially alike 19. 

 18b. Perianth differentiated into sepals and 2 or 3 colored petals 

 21. 



