KEY TO COMMON DECIDUOUS TREES IN 

 WINTER. 



Of the technical expressions used in the following key a few which 

 are not usually found in glossaries or are not self-explanatory may 

 need definition. The leaf-scar is here' understood as the scar left 

 by the petiole or leaf-base exclusive of the stipules. The stipule- 

 sears when present appear mostly as small triangular or linear 

 ijiarks either side of the upper edges of the leaf-scar, and may 

 sometimes encircle the stem. Within the leaf-scars and sometimes 

 in the stipule-scars appear traces of the flbrovascular bundles which 

 were continued into the framework of the leaf. These are bundle- 

 soars, and usually take the form of minute dots or projections. As 

 applied to leaf-scars the terms oval and elliptical are here under- 

 stood as implying, respectively, elongation lengthwise and cross- 

 wise of the twig. Spurs are short, secondary shoots in which there 

 may be many internodes much abbreviated. A rank of bud-scales, 

 leaf-scars or spurs is a row parallel to the axis. All the structures 

 mentioned in this kej- may be seen with a hand lens magnifying 

 twenty diameters. 



I. LEAF-SCARS ALTERNATE. 



A. Buds covered ly a single scale. 



Sallx (Willows) . Bud-scale with two lateral ridges. End bud not 

 larger than the others. Bundle-scars three. Stipule-scars small. 



Magnolia (Magnolias) . Bud-scale with two lobes (stipules) attached 

 to base of petiole. End bud much larger than the others. Bundle-scars 

 many. Stipule-scars encircling stem. 



B. Buds covered by a few scales or rudimentary leaves, often very hairy. 

 1. Stipule-scars encircling stem. 



Iiirlodendron Tullplfera (Tulip Tkee). Leaf-scars large, semi- 

 oval. Bundle-scars numerous. Bud-scales dotted. 



Pl^tanus (Plane Trees). Leaf-scars encircling the buds. Bundle- 

 scars five. Bud-scales smooth. 



