38 SYSTEMATIC POMOJ.nGY 



beset witli glandular liairs. The serrations of the margins often 

 furnish serviceable taxonomie charadei-s ; in one si)eeies the 

 margins are so laciniated as to <rive the njinic liiihiis hiciiiiaf us 

 to the group. In some sjieeies the teeth are in a single series; 

 in others in a (l()ul)le row. These characters of leaves pei-sist 

 in cultivated plants. 



63. The leaves of the bush-fruits. — in currants and «roose- 

 l)errics the upper surfaces of the leaves difTei* as to whether dull 

 or "flossy, as well as in many characters luimed in the preceding 

 paragrai)lis. The leaves of some curi-ants are blistered or 

 puckered, sometimes called huUate. The nuirgins of the leaves 

 of species and varieties vary greatly in the amount and character 

 of pubescence, and in several varieties they take on a pronounced 

 silvery tint, a mark which identifies the Ruby currant. The 

 leaves of Ribes are more or less rugose, but the veins are more 

 sunken in some sj^ecies than in others and the spaces between 

 more elevated. The degree of rugoseness is a particularly val- 

 uable mark in distinguishing some gooseberries. 



64. Identification of nursery trees from the leaves.— Shaw 

 has shown that trees can be identified in the nursery from leaf 

 characters alone, and gives a key w^hereby twenty-six standard 

 apples are classified by his method." While Shaw has not pub- 

 lished on other fruits, there is little question but that all fruits 

 can be so classified. To be able to identify young trees from 

 their foliage is of particular importance to nurserjonen and 

 buyers of nursery stock who want to make sure that trees are 

 true to name. 



= Shaw, J. K. Leaf Characters of Apple Varieties. Bull. 208 : Mass. Agr. 

 Exp. Sta. 1922. 



