II] STIPULATE LEAVES 21 



Rhamnus Frangula Robiuia Sarothamnus 



Laburnum Prunus Pad us Blackthorn 



Cherry Prunus Avium Roses 



Blackberry Viburnum Opulus Salix triandra 



Salix pentandra S. Caprea 8. aurita 



S. cinerea Hazel Hornbeam 



Birch Alder. 



The following have deciduous or caducous stipules, 

 i.e. they fall at once on or soon after the emergence of 

 the leaf from the bud : 



Tilia Ampelopsis Vine 



Spindle Tree Rhamnus Catharticus Pear 



Apple Pyrus torminalis Pyrus Aria 



Rowan Hawthorn Black Currant 



Gooseberry Red Currant Viburnum Lantana 



Elder Elms Poplars 



Oaks Beech Salix fragilis, 



and many other Willows. 



If the student collects a number of common simple 

 leaves, noticing at the time that he is taking average 

 specimens of the foliage, he soon becomes convinced that 

 there is some relative stability of form, and that a type- 

 shape can be chosen for each kind from which the rest 

 of the foliage does not usually depart very much. Absolute 

 geometrical constancy he will not find, and some plants 

 show far more variety than others ; but in cases like the 

 following, most of the leaves on the plant or tree will be 

 found fairly exemplified by any normal specimen. 



Suppose we take average leaves of Scotch Pine, Yew, 

 Hypericum, Beech, and common garden Nasturtium 

 (Tropceolum), we shall find that they conform most nearly 

 to the following geometrical outlines, termed acicular, 

 linear, oblong, oval (or elliptical), and sub-rotund in order 



