WATSIDE WEEDS. 115 



nettle leaf, the stipules are small, but at tlie base of 

 the petiole of the compound rose leaf (Fig. 73), or 

 in many vetches, and ia the clover (Fig. 74), yon 

 will find the stipules much more fiilly developed. 

 The poiut of junction of the leaf-petiole with the 

 stem of the plant from which it springs (Fig. 72, d), 

 is called the axil or axilla, and from the angle, 

 formed by the two, frequently spring leaves, flowers, 

 or buds (Fig. 69, etc.) As the ribs and veins of a 

 leaf give it form, and govern, hkewise, its irregu- 

 larities, the intervening green pulp, or, as botanists 

 call it, parenchyma, makes up its substance, both 

 being covered over with the skin, or epidermis, of 

 the plant. Much is there to tell of the beautiful 

 and important functions performed by leaves, through 

 their veins, parenchyma, and epidermis ; but we have 

 too much to say of their outside forms to enter into 

 these things now. 



It seems superfluous to remind the reader that a 

 leaf has two surfaces, but we do so to direct the 

 attention to the difierence in these surfaces in every 

 leaf you examine, that difference being, of course, 

 much greater in some than iu others. The chief 

 appendages attached to leaves are hairs of very 

 varied form, from the softest down, or the satiny 

 lustre of the mountain lady's-mantle, to the sting 

 of nettle, which is a glandular hair, or the prickle, 

 or seta, of the rose-leaf, or rose or bramble stem 

 (Fig. 73) ; the seta being in reality hardened hair. 



