KEY TO THE ORDERS. XX111 



A. Perianth superior (adherent to the ovary)* 



*. Flowers dioecious or polygamous, regular. 



HYDROCHARIDACE.E. Aquatics. Pistillate flowers only 



above water ; perianth of 6 pieces 226 



DIOSCOREACE^E. 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 



IRIDACE.E. Stamens 3 235 



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



bulb 236 



B. IN i i an I h Inferior (free from the ovary). 



ALISMACE^E. Pistil apocarpous : carpels in a ring or head, 



leaves with distinct petiole and blade 224 



SMILACEJE. 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 



LILIACE^. 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^. 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^. Perianth wholly glumaceous, of similar pieces. 243 



XYRIDACE^. Perianth partly glumaceous ; inner set of 3 



yellow petals. Flowers in dense heads, perfect . 247 



ERIOCAULONACE^E. In shallow water. Flowers monoecious 

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

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

 base 247 



