46 THE TRUNK. PART I. 



but in some species *fStkantts>>Scirpm, and Cypress- 

 grass, they are triangular. In their structure they 

 are generally hollow or tubular, as in the straw of 

 Wheat : but in some genera they are solid, as in the 

 straw of the Bulrush. The hollow straw is generally 

 jointed with large swollen knots at the joints, as in 

 Oats and Barley ; but most of the rushes are with- 

 out joints, though many of them are still tubular, 

 having their transverse partitions at regular inter- 

 vals without external knots. Some of the grasses 

 have a peculiar and strongly marked bend at the 

 knots, and then they are said to be knee-jointed, as 

 Alopecurus geniculatus. 



SUBSECTION III. 



The Stipe.The stipe is a sort of secondary trunk 



(P/.I. Fig. 12.), at least as applicable to the class of 



Asdis- plants now under consideration, and is peculiar to 



tinguish- _^ . _ . r , 



ablefrom Palms. It issues from the root or from the sum- 

 Indculm. mii f *^ e ma ^ n stem, and supports the foliage, 

 though it has but little that is analogous to the 

 stem either in its shape or mode of growth ; its 

 shape being similar to that of leaves in its exhibit- 

 ing two sides ; and the shape of the main stem 

 being that of the shaft of a column, cylindrical 

 but without knots, and nearly of the same diameter 

 throughout ; as well as advancing in height by means 

 of annual additions to the summit only, the diameter 

 of the first year being the maximum. 



