14. HAIRS AND EMERGENCES. 



47 



from the roots of a number of aquatic plants (e.g. Butomus um- 

 bellatus, Caltha palustris, Hippuris, Myribphyllum, Menyanthes, 

 Nymphaea, Lemna) ; they may be developed on the thallus, or the 

 thalloid shoot, in the gametophyte of Liverworts and homo- 

 sporous Vascular Cryptogams ; on the stem, thpugh rarely (e.g. 



Fio. 31. Different form of hairs. A Branched compound hair (Verbascum). E b 

 Stinging-hair with basal cushion p ; ?i simple hair (Urtica). C Branched simple hair, 

 seen from the surface ; e epidermis (Matthiola). D Scaly compound hair (Hippophae) ; a 

 seen from the surf ace; b seen in section; c central cell; r radiating cells; s stalk-cell ; e 

 epidermis. E Ramentum (Asplenium) ; b the point of attachment. 



Corallorhiza, Epipogum, Psilotum), or even on leaves. They are 

 always unicellular, and it is only rarely that they are found 



