CHAP. III.] BUTOME^. 437 



head, as in the Ranunculus tribe. A, natans^ 

 which is generally found on lakes in the moun- 

 tainous districts of Wales and Cumberland, has 

 rather large white flowers, with a yellow spot at 

 the base of each petal. The flower-stalks rise 

 high above the water, and the flowers expand 

 in the months of July and August. The com- 

 mon Arrowhead {Sagittaria sagittifolia) has 

 curiously-shaped leaves, resembling the head of 

 an arrow. The flowers are white, and resem- 

 ble those of A. natans ; but they have a pink 

 spot at the base, and there are numerous 

 stamens. The flowers are in whorls, and those 

 in the upper whorls are generally destitute of 

 carpels. The common Star-fruit {Actinocarpus 

 damsonium) has only six carpels, which are so 

 arranged as to form a star-like fruit when ripe. 



ORDER CLXXXI.— BUTOMEtE.— THE FLOWERING 

 RUSH TRIBE. 



The flowering Rush {Butomus umhellatus) is 

 certainly the handsomest of the British aquatic 

 plants. The flowers are rose-coloured, crimson, 

 or white ; and they are produced in large erect 

 umbels. The calyx and the corolla are gene- 

 rally of the same colour, and in three divisions 

 each ; there are nine stamens and six capsules, 

 which are many-seeded. The leaves are trian- 



