XXIV KEY TO TIIK ORDERS. 



Triglochin, in 



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

 or raceme. Carpels when ripe splitting away from 

 a persistent axis 147 



LILIACE^S. Perianth of similar divisions or lobes, mostly 6, 

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

 division, the stamens similar 158 



Trillium, in 



LiLiACEvE. Perianth of 3 green sepals and three coloured 



petals 158 



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



(blue or yellow) tubular, of 6 lobes. Aquatics 164 



JUNCACE^E. Perianth glumaceous, of similar pieces 162 



ERIOCAULONACE.E. In shallow water. Flowers in a small 

 woolly head, at the summit of a 7 -angled scape. 

 Leaves in a tuft at the base 165 



III. GLUMACEOUS DIVISION. 



Flowers without a true perianth, but subtended by thin scales 

 called glumes. 



CYPERACE.E. Sheaths of the leaves not split 165 



GRAMINE^:. Sheaths of the leaves split on the side away 



from the blade 168 



SERIES II. CRYPTOGAMS. 



Plants without stamens and pistils, reproducing themselves by 

 spores instead of seeds. 



CLASS III. PTERIDOPHYTES. 



Stems containing vascular as well as cellular tissue. 



FILICES. Spores produced on the fronds 174 



EQUISETACE^E. Spores produced on the under side of the 



shield-shaped scales of a terminal spike or cone. . . 181 

 LYCOPODIACE^:. Spore-cases produced in the axils of the 



simple leaves or bracts 182 



