A lismacetfSagittaria. 465 



1. S. sagittifblia (fig. 225). Arrow-head. This is the only 

 one that need occupy our attention. It is a common plant in 

 the South of England, about a foot high, with ephemeral uni- 



Pig. 225. Sagittaria sagittifolia. (i nat. size.) 



sexual flowers an inch or more in diameter, white with a purple 

 centre. Segments of the perianth all similar ; stamens nume- 

 rous. It blooms throughout the Summer. 



2. BtTTOMUS. 



This is a genus comprising one or two very elegant aquatic 

 plants with slender erect triquetrous leaves and a tall scape 

 surmounted by a large umbel of rosy-pink flowers. Perianth- 

 segments free, equal, all coloured. Stamens 9. Carpels about 

 6, many-seeded. The derivation of the generic name is ob- 

 scure. 



1. B. umbellatus. Flowering Rush. One of our handsomest 

 native aquatics and the only British plant having 9 stamens. 

 It grows from 3 to 6 feet high according to conditions, and 

 flowers at Midsummer. 



Aponogeton distdchyus is a handsome aquatic plant, re- 

 markable for its floating branched spikes of small fragrant 

 bracteate white flowers. Leaves oblong-lanceolate, on long 

 petioles, floating. This plant is a native of the Cape of Good 

 Hope, but it will flourish in a lake or stream if planted at a 



