1 8 4 



BUDS AND BRANCHES 



so, is it a cluster or a single flower ? (Terminal buds in 

 the tulip tree are usually, but not always, flower buds.) 

 Remove the next pair of scales and notice the rudimentary 

 leaf between them. This outer leaf is often found to be 

 dead ; can you account for the fact ? Pick off the succes- 

 sive pairs of scales, noticing the leaf between them. 

 Observe that the footstalk of each originates between the 

 bases of the scales. You will have no difficulty now in 

 identifying the little round dots in your cross section as the 

 cut ends of the petioles. How many pairs of scales are 

 there in the bud ? How many leaflets ? Study their 

 arrangement and compare it with the diagram (Fig. 337). 

 How does this correspond with the arrangement of leaves 

 on the stem ? Do you find any clusters of bud scale 

 scars as in the other specimens examined? 



258. What the Scales are. The bud scales here clearly 

 can not represent leaves. Compare their position at the 

 foot of the petiole with what was said in Section 32 regard- 

 ing the stipules, and 

 decide what they are. 

 Notice that the two 

 hard outer ones have 

 no leaflet between them ; 

 this is because they are 

 the stipules left by the 

 last leaf of the preced- 

 ing season, which per- 



338. Elm bud with succession of scales: s j s <- on t h~ crpm rhniio-h 

 t. terminal bud. The scales are numbered in ' tem ' tn U g n 



successive order as they occur at the nodes, the Others Usually fall 

 9 shows two stipular scales partly fused into 

 one ; 10, an outer and an inner stipule, o. st 

 and /. st, with a rudimentary leaf between; n, 

 12, and 13, the same. All are separated to 



the 



show outline. 



away soon after 

 leaves develop. 



In the elm each scale 

 represents a pair of 



stipules, as will be evident by observing that they are 

 often notched or bifid at the top, and that the rudiment- 

 ary leaves stand opposite their scales instead of between 

 them. 



