Key to THI! orders. -inrm 



A. Periauth superior (adherent to the ovary). 



* Flowers dimcious or polygamotis, regular. 



Hydrocharidace^. — Aquatics. Pistillate flowers only 



above water ; perianth of 6 pieces 226 



DiosoorkacEjG. — Twiners, from knotted rootstocks. Leaves 



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



* * Flowers perfect. 



Orchidace^. — Stamens 1 or 2, gynandrous. Plowers irreg- 

 ular 226 



Ibidace^. —Stamens 3 235 



Amaryllidacb^. — -Stamens 6. Flowers on a scape from a 



bulb 236 



B. Periauth Inferior (free from the ovary). 



AlismacejE. — Pistil apocarpous : carpels in a ring or head, 



leaves with distinct petiole and blade 224 



SmiLAOEiE. — Climbing plants, with alternate ribbed and 



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



Trigloehin, in 



ALiSMACEiE. — Rash-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 



P0NTEDERIACE.E. — Stamens 6, 3 long and 3 short. Perianth 



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



JttncacejE. — Perianth wholly glumaceous, of similar pieces. 243 



Xyridaoe^. — Perianth partly glumaceous ; inner set of 3 



yellow petals. Flowers in dense heads, perfect . 247 



Eriocaulonacb^. — 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 



