CHAPTER LXVI. 



CLASSIFICATION OF THE ANGIOSPERMS. 

 Group Angiospermse. 



I. CLASS MONOCOTYLEDONES. 



1190. Order Pandanales. Aquatic or marsh plants. The 

 cattail flags (Typha) and the bur-reeds (Sparganium), each rep- 

 resenting a family. The name of the order is taken from 

 the tropical genus Pandanus (the screw-pine often grown in 

 green-houses). 



1191. Order Naiadales. Aquatic or marsh herbs. Three 

 families are mentioned here. 



The pondweed family (Naiadaceae), named after one genus, 

 Naias. The largest genus is Potamogeton, the species of which 

 are known as pondweeds. Ruppia occidentalis occurs in 

 saline ponds in Nebraska, and R. maritima along the seacoast 

 and in saline districts in the interior. 



The water-plantain family (Alismaceae) includes the water- 

 plantain (Alisma) and the arrow-leaves (Sagittaria). 



The tape-grass family (Vallisneriaceae) includes the tape-grass, 

 or eel-grass (the curious Vallisneria spiralis). 



1192. Order Graminales. Two families. 



The grass family (Gramineae), the grasses and grains. 

 The sedge family (Cyperaceas), the sedges. 



1193. Order Palmales, with one family, Palmaceae, includes 

 the palms, abundant in the tropics and extending into Florida. 

 Cultivated in greenhouses. 



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