58 Elementary Work in Botany. 



lobed leaves are pinnately or palmately parted (Fig. 46, b 

 and e). Divided leaves are cut quite to the midrib if 

 pinnately, or to the base if palmately divided. Leaves are 

 cleft when the sinuses between the lobes are sharp. It is 

 common to give the number of lobes in the descriptive 

 phrase. In Fig 46, c is palmately five-lobed, and e is 

 palmately five-parted. Pinnately lobed, parted, and divided 

 leaves come under the general term pinnatifid. When the 

 lobes are pinnatifid the leaf is bi-pinnatifid. 



Compound leaves have distinctly separated leaflets, which 

 are joined to a common petiole in palmate leaves (Fig. 47, 

 #), and to a prolongation of it called a rachis in pinnate 

 leaves (Fig. 46, d]. Clover leaves are usually palmately 

 3-foliolate. Bur-clover is pinnately 3-foliolate (Fig. 47). 

 An abruptly pinnate leaf has no terminal leaflet. Leaves 

 may be twice or thrice compound; that is, the leaflets may 

 be compound. Such leaves are said to be decompound. In 

 a tri-pinnate leaf the leaflets of the leaflets are pinnate. 



Keep all your leaves * and find if you can other kinds 

 for the next exercise. Leaves of locust, ailantus (tree of 

 heaven), acacia, lupine, strawberry, elderberry, etc. may 

 be added to your collection. 



EXERCISE 33. 



Decompound Leaves. Have you a compound leaf, 

 with compound leaflets; that is, decompound ? Is it of the 



* Do not be so slovenly as to put leaves or flowers in any useful book. Find 

 one useless for any other purpose; an old almanac, for example. A blank book 

 in which finally to fasten the leaves after they are dry is desirable as a record of 

 your work. 



