382 



THE RIVER-SIDE NATURALIST. 



finger at the base, sometimes from 6 ft. to 8 ft. long. The 

 flower husks (glumes) are fringed with brown. The stems 

 are much used for mats, chair-bottoms, &c., and form a 

 considerable article of trade. Coopers use them for filling 

 up the spaces between the staves of casks. There are 

 seven British species. Flowers July. 



At the bottom of ponds and slow-flowing rivers, par- 

 ticularly where mud has accumulated, the COMMON HORN- 

 WORT (Ceratophyllum demersum) 

 Fig. in "E. B.," 1276 

 (from kercs, a horn, andphyllon, 

 a leaf, they being branched like 

 a stag's horn), grows in con- 

 siderable quantity. The stems, 

 which float entirely under 

 water, and at times form a 

 portion of "the floating weeds," 

 are long and slender, and much 

 branched ; the leaves, in 

 whorls, are, thin, slender, and 

 green in 'colour. The flowers 

 are found in the axil of the 

 leaves, which towards the 

 upper extremity become very 

 plumose. It is a very elegant 

 plant, and affords shelter for 

 many kinds of fish. There are 

 two species the above, and 

 C. submersum, distinguished 

 by the leaves being more feathery and having no spines to 

 the fruit. Flowers July. 



One of the commonest of our water-plants, cultivated to 

 a very great extent as an addition to our breakfast-tables, 

 is the WATERCRESS (Nasturtium ojfidnale] Fig. in " E. B.," 

 125 named from Nasus tcrtus, a convulsed nose, an effect 

 supposed to be produced by the acid and pungent quality 

 of this plant. The stems are spreading and creeping ; 

 leaves alternate, smooth, shiny, deep green ; flowers small 

 white, some with a purplish tinge. The wild form which 



COMMON HORNWORT. 



