KEY TO THE ORDERS. XX1U 



A. ivriaiit h superior (adherent to the ovary). 



* Flowers dioecious or polygamous, regular. 



HYDROCHARIDACE^E. Aquatics. Pistillate flowers only 



above water ; perianth of 6 pieces 226 



DIOSCOREACE^. Twiners, from knotted rootstocks. Leaves 



heart-shaped, net- veined. Pod with 3 large wings. 236 



* * 



Flowers perfect. 



ORCHIDACE.E. Stamens 1 or 2, gynandrous. Flowers irreg- 

 ular 226 



IRIDACELE. Stamens 3 235 



AMARYLLIDACE^E. Stamens 6. Flowers on a scape from a 



bulb 236 



B. Perlauth inferior (free from the ovary). 



ALISMACE.*;. Pistil apocarpous : carpels in a ring or head, 



leaves with distinct petiole and blade 224 



SMILACE^E. Climbing plants, with alternate ribbed and 



net- veined petioled leaves. Flowers dioecious . . . 237 



Trigloehin, in 



ALISMACE^E. Rush-like marsh herbs. Flowers in a spike 

 or raceme. Carpels when ripe splitting away 

 from a persistent axis 224 



LiUACEjE. Perianth of similar divisions or lobes, mostly 

 6, but in one case 4. One stamen in front of each 

 division, the stamens similar 237 



Trillium, in 



LILIACE^E. Perianth of 3 green sepals and three coloured 



petals 237 



PONTEDERIACE.E. Stamens 6, 3 long and 3 short. Perianth 



(blue or yellow) tubular, of 6 lobes. Aquatics. . 247 



JUNCACE^E. Perianth wholly glumaceous, of similar pieces. 243 



XYRIDACE^E. Perianth partly glumaceous ; inner set of 3 



yellow petals. Flowers in dense heads, perfect. 247 



ERIOCATTLONACE^:. In shallow water. Flowers monoacious 

 or dioecious, in a small woolly head, at the sum- 

 mit of a 7 -angled scape. Leaves in a tuft at the 

 base ; 247 



