PISTIACE.E. DUCK-WEED TRIBE. 643 



aquatic plant, with somewhat of the habit of a sedge 

 or large grass. It is easily distinguished from all other 

 British plants by its peculiar spadix, and the fragrance 

 of its roots, stems, and leaves. Fl. June. Perennial. 



OBD. XCVIL PISTIACILE. DUCK-WEED TRIBE. 



Minute floating plants, composed of simple or lobed 

 learns, and fibrous roots, which are not attached to the 

 soil, propagating themselves principally by offsets, but 

 sometimes producing on the edge of the leaves 1 2 

 stamens, and 1 4 seeded ovaries, enclosed in small 

 sheaths. Lemna (Duck-weed) is the only British ex- 

 ample, and the number of foreign species is but 

 small. 



LEMNA MINOR (Lesser Duck-weed). 



1. LEMNA (Duck-weed). 



I. L. minor (Lesser Duck- weed). A minute plant, 

 but often so abundant as to cover the surface of stagnant 

 water, where, with the insects which it harbours, it is 

 greedily devoured by ducks. In this species the leaves 

 are egg-shaped, and bear each a single root. Three 

 other species have been found in Britain, for a description 

 of which the student is referred to " Hooker and Arnott's 

 British Botany." 



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