146 FLOWERS OF LAKES, RIVERS, ETC. 



are in pairs, the stij^mas sessile and very smalt. The flowers are 

 sweet-scented. The plant is not usually fertile in the British Isles, as 

 it is in Asia, the proper insects being absent here. 



The fruit, which does not ripen in Europe, is a berry, which falls 

 when ripe, being full of mucus, into the water or to the ground, and 

 is thus dispersed. 



Sweet Flag is entirely a peat-loving plant, growing in peat soil. 



Aco)-2is, Dioscorides, is from acoros, the Greek name of the plant; 

 and Calamtis, Dioscorides, is from the Greek ca/aii/os, a reed. 



Sweet Flag is named Beewort, Cinnamon Sedge, Myrde and Sweet 

 Flag, Myrde-flag, Myrtle-grass, Myrtle-sedge, Sweet Seg, Sweet 

 Sedge, Sweet Rush. 



Powdered, the root has been used in lieu of spices. It is a stimu- 

 lant and tonic. When bruised, the leaves smell sweet, hence it was 

 used to strew the floors of houses. It yields an essential oil, obtained 

 by distilling it. It has been used for fevers and ague. The roots are 

 carried abroad, eaten as sweetmeat, and used as a means of avoiding 

 contagion. As orris-root it is used as a tooth powder. 



Essential Specific Characters: — 



312. Aconts Calamus, L. — Stem terminating in a spathe, leaves 

 long, ensiform, radical, 2-edged, like the scape, flower (spadix), lateral. 



Duckweed (Lemna minor, L.) 



Although Duckweed is almost ubiquitous in its distribution it is 

 not found, as can hardly perhaps be expected from its small size 

 and fragile nature, in early plant-beds. In Great Britain it is found in 

 every county except Radnor, Peebles, Sutherland, and the Shetlands, 

 that is, it ranges as far north as the Orkneys. In Derbyshire, more- 

 over, it is found at the height of 1200 feet. It is a native of both 

 Ireland and the Channel Islands. 



Duckweed is so common that one expects to find it in every acjuatic 

 habitat, but it is more addicted to still than running water, as, tor 

 instance, that in ditches, drains, ponds, pools, lakes, meres, and that in 

 slow-flowing rivers. It is a member of the floating-leaf association. 



There is a single root hanging down from the floating, flat, inversely 

 egg-shaped froiul, with no stem or leaf The frond is subconvex 

 below, and flattened at the sides. The young fronds are seated at 

 first on older ones but become detached. Below they are paler green 

 than above. They are compact, and the cells of the epidermis are 

 lined with waw walls. 



