xxix 



I9a. Flowers in umbels 20. 



19b. Flowers in dense round heads; petals 5 



2a, in TJMBELLIFERAE, p. 80, 

 19c. Flowers in spikes, racemes, or panicles 



38, in LILIACEAE, p. 13. 



20a. Ovary inferior, appearing below the perianth as a swelling 

 at the apex of the stalk; flowers bright yellow; leaves linear 



AMAKYLLIDACEAE, p. 14, 



20b. Ovary inferior; flowers blue or white, terminating a flat- 

 tened winged leafless flower-stalk 3a, in IRIDACEAE, p. 15. 



20c. Ovary superior, i. e., in the center of the flower and sep- 

 arate from the perianth 31, in LILIACEAE, p. 13. 



21a. Flowers in dense heads, yellow, 1 cm. wide or smaller 



XTRIDACEAE, p. 9. 

 21b. Flowers in umbels, blue or white, 2 cm. wide or larger 



COMMELINACEAE, p. 9. 



22a. Flowers blue; ovary superior (defined under 20c) ; stamens 

 distinct from the other parts of the flower 23. 



22b. Ovary inferior (defined under 20a) ; floral structure com- 

 plex; stamens attached to other parts of the flower and not 

 resembling ordinary stamens in form or structure 



ORCHIDACEAE, p. 15. 



23a. Leaves triangular-heart-shape at base; marsh plants 



la, in POIVTEDERIACEAE, p. 10. 

 23b. Leaves not heart-shape at base COMMELINACEAE, p. 9, 



