60 
THE FLOWERING PLANT. 
In the former case, the petiole is continued into what is evidently 
the common leaf-stalk, at the base of which are jointed a pair of 
Fig. 24.—Pinnate 
Leaf. 
leaflets, while it is terminated by an odd leaflet 
jointed in the same manner. This, then, is a 
pinnate leaf. The three leaflets in the clover 
are all attached to the end of the petiole, which 
is the only common leaf-stalk. We have here, 
therefore, a palmate leaf. The general appear- 
ance, however, is usually a sufficient guide. 
The leaflets of the palmate leaf are either all 
sessile or with stalks of equal length, while in 
the abbreviated pinnate leaf the terminal leaflet 
appears to be stalked even when the other two 
are sessile, for the common leaf-stalk seems 
to belong to it. Similarly, when the lateral 
leaflets are stalked, the terminal one apparently 
has a longer stalk. The lower part of this 
apparent stalk is, however, common leaf-stalk. 
A compound leaf may even be reduced to one 
leaflet, and is then liable to be mistaken for 
a simple leaf. In the barberry, for example, 
the small leaves are jointed on short stalks. A 
simple leaf is not jointed in this way upon its 
petiole. ‘The inference that it is a reduced com- 
pound leaf is borne out by comparison with the closely allied 
yellow-flowered mahonias frequently found in gardens. Here 
FIG. 25.—Ternate Leaf of Fig. 26.—Palmate Leaf of Horse- 
Strawberry. Chestnut. 
the leaves are normally pinnate, with a terminal and two to four 
pairs of lateral leaflets. The ash presents a similar case. The 
