TEE COMPOUND LEAF 41 



with the multitude of forms. We are also 

 impressed with the fact that there may be 

 great variety, or elasticity, of forms in the 

 same kind of plant, showing that nature is really 

 informal. Definitions, however, are formal ; and 

 it, therefore, follows that definitions should be 

 compared with the objects, not the objects with 

 the definitions. 



The terminology (or naming) of compound leaves may be further 

 explained, as follows: 



49a. In making compounds to express the number of leaflets, the 

 Latin for leaflet (foliolum) is used, not the word for leaf (folium); a 

 trifoliate leaf is, therefore, an impossibility. It is like saying "three- 

 leaved leaf." However, usage has sanctioned its employment, although 

 it is etymologic ally improper. The better forms are 

 TJnifoliolate, a compound leaf of one leaflet; 

 Bifoliolate, of two leaflets; 

 Trifoliolate, of three leaflets; 

 Quadrifoliolate, of four leaflets; 

 Quinquefoliolate, of five leaflets; 

 Plurifoliolate, of several or many leaflets. 



Any of these terms may be applied to either digitately or palm- 

 ately compound leaves. 



49b. The degree of compounding is often specified as follows: 

 Compound, once compound, 

 Bi-compound, twice compound, etc.; 

 De-compound, more than once compound, without specifying the 



degree. 



Similarly, pinnately compound leaves may be designated as bipin- 

 nate, tripinnate, etc. ; and palmately compound ones as bipalmate, tri- 

 palmate, etc. As a matter of fact, palmate leaves are rarely decom- 

 pound if they have more than three primary divisions; so that it is 

 customary to speak of palmately compound leaves as ternate, biternate, 

 tritentate, multiternate, etc. 



SUGGESTIONS. The venation of a leaf (or petal) is the arrange- 



