XXll 



EXPLANATION OF TERMS. 



Pinnate Leaves are forms of compound leaves in which the blade is split 

 and the leaflets arranged at the sides of the midvein, after the same manner 

 as leaves are pinnately veined. (Fig. 3.) Varieties of this form are these : 



Abruptly Pinnate : wherein the leaf is terminated by a pair of leaflets. 



Odd Pinnate : when one leaflet terminates the midvein, or again the 

 terminal leaflet of this form, as in many vines, is changed into a tendril. 



Palmately Compound Leaves have leaflets spreading from a common 

 point at the base and follow the manner of palmately-veined leaves. 



Leaves may be twice, thrice or more times compound when they are de- 

 scribed by such terms as decompound, divided more than once ; bipinnate, 

 meaning twice pinnate (FiG. 4) ; ternately compound, divided into seg- 

 ments of threes, etc. 



Always are their leaflets subject to the same variations in construction as 

 are simple leaves, and that some of their most common forms maybe readily 

 known the following terms are in use : 



FIGS. 19, 



23, 24, 



25, 



26, 



27, 



28. 



Filiform : very fine, thread-like. 



Linear : when the leaf is several times longer than broad ; grass-like. 

 (Fig. 23.) 



Lanceolate : long and narrow ; broadening at or near the base and 

 pointed at the apex. (FiG. 21,) 



Oblanceolate: a reversed lanceolate. 



Oblong : two or three times longer than broad and rounded at the ex- 

 tremities. (Fig. 25.) 



Elliptical : the same as oblong, but tapering at both ends. (Fig. 12.) 



Oval : broadly elliptical. 



Ovate : when the outline is like the long section of an egg, the larger end 

 being downward. (Fig. 26.) 



Obovate: a reversed ovate. (Fig. 15.) 



