140 WAYSIDE WEEDS., 



you remember tlie division of vegetables to wHch 

 the grasses belong — tbose witb one-lobed seed* 

 and straigbt-veined leaves^ but wliicli also bear the 

 name of endogenous plants, from the peculiar mode 

 of growtb of tbe stems, which have their annual 

 additions of new material made to the centre. 

 This mode of growth we cannot see exempHfied 

 in the herbaceous grass, or indeed in any of our 

 native endogens, but the giant palms of the tropics, 

 could we get at them, would show not only this 

 peculiar stem structure, but the noblest specimen 

 of the simple, unbranched stem. Call to mind the 

 pictures you have seen of some palm-clad island of 

 the Southern Seas, and you will remember the 

 simple stem of these beautiful and stately trees. 

 To return to the grass stem (Fig. 87), examine it 

 further. It is hollow, hence called fistulous] its 

 hollow column, strong in itself, considering the 

 amount of material, is further strengthened by 

 knots or thickenings, at which a partition or 

 diaphragm is thrown across the tube (Fig. 87, a). 

 Moreover, the exterior of the green grass tube 

 is smooth and shining from its coating of silex 

 or flint substance. A wonderful combination of 

 strength, hghtness, and slender grace have we in 

 the simple grass stems. The sedge of thQ water^ 

 side has also a simple stem and straight^veined 

 leaf, but the stem is sharply triangular (Fig. 88, s), 

 and has no knots, We go back to stems generally ; 



