4 TREES 



approaches, to accept the invitation of the south wind and 

 sun. 



The protective scale leaves fall when they are no longer 

 needed. This vernal leaf fall makes little show on the 

 forest floor, but it greatly exceeds in number of leaves the 

 autumnal defoliation. 



Sometimes these bud scales lengthen before the shoot 

 spares them. The silky, brown scales of the beech buds 

 sometimes add twice their length, thus protecting the 

 lengthening shoot which seems more delicate than most 

 kinds, less ready to encounter unguarded the wind and the 

 sun. The hickories, shagbark, and mockemut, show scales 

 more than three inches long. 



Many leaves are rosy, or lilac tinted, when they open — 

 the waxy granules of their precious "leaf green "screened 

 by these colored pigments from the full glare of the sun. 

 Some leaves have wool or silk growing like the pile of velvet 

 on their surfaces. These hairs are protective also. They 

 shrivel or blow away when the leaf comes to its full de- 

 velopment. Occasionally a species retains the down on 

 the lower surface of its leaves, or, oftener, merely in the 

 angles of its veins. 



The folding and plaiting of the leaves bring the ribs and 

 veins into prominence. The delicate green web sinks 

 into folds between and is therefore protected from the 

 weather. Young leaves hang limp, never presenting their 

 perpendicular surfaces to the sun. 



Another protection to the infant leaf is the pair of stipules 

 at its base. Such stipules enclose the leaves of tulip and 

 magnolia trees. The beech leaf has two long strap-like 

 stipules. Linden stipules are green and red — two con- 

 cave, oblong leaves, like the two valves of a pea pod. Elm 



