68 LEAVES. 



(38) Henbane Leaves. 



The leaves of Hyoscyamus niger, Linn. (N.O. Solanaceee). 



The epidermis of both surfaces is composed of cells with very 

 wavy walls and smooth cuticle ; they vary from 40 to lOO/x in 

 length. Both surfaces bear simple and glandular hairs, as well as 

 stomata. The latter are broadly oval, and surrounded by three 

 or four cells, one of which is smaller than the others; this 

 arrangement is commonly met with in solanaceous plants. The 

 stomata average about 23-27^ in length. The simple hairs are 

 uniserial and conical, and have thin walls. The glandular hairs are 

 usually long, uniserial, and terminated by a small bicellular gland? 

 or by a large ovoid pluricellular one. 



The mesophyll is heterogeneous and asymmetrical ; the cells of 

 the spongy parenchyma often contain prismatic crystals of calcium 

 oxalate. 



The midrib is biconvex. The wood is curved, and has bast both 

 above and below it, bicollateral bundles being constant in the- 

 natural order Solanacese. Neither bast nor pericycle contains any 

 lignified elements. 



The diagnostic characters of powdered henbane leaves are : 



(a) The remarkable glandular hairs. 



(b) The calcium oxalate, mostly in prisms. 



(c) The epidermal cells with wavy walls. 



^d) The stomata surrounded by three or four cells, one of which is: 

 larger than the others. 



(e) The absence of pcricyclic fibres. 



