42 XOMKXCLATURE. 



47. 



A leaf is called pinnated (pinnatian), when it consists of 

 several distinct leaves, which spring along the sides of a com- 

 mon leaf-stalk; (Tab. VI. Fig. 11.) The common leaf- 

 stalk is called the pctiohis communis, as also the axis and 

 rachis. 



Pinnated leaves are classed according to the position of the 

 individual leaflets (pinnae). When these stand opposite to 

 one another {opposite pinnata), they are reckoned by pairs 

 (jugum), and the leaves are said to be two-paired, three- 

 paired, four-paired, and so forth {bl- tri- quadri-juga). At 

 other times, however, the leaflets alternate with one another 

 {alternatim pinnata). If the summit of the whole leaf termi- 

 nate with an unpaired leaflet, it is then said to be impari-piiv- 

 natum : when there is no unpaired leaf on the point, th(j leaf 

 is said to be abruptly pinnated (abrupte pinnatum). 



When, between the proper side-leaves, smaller leaflets are 

 placed alternately, the whole leaf is said to be interrupted- 

 ly pinnate (jnter7upte pinnatum), as in Agrimonia Eupato- 

 ria. When the side-leaves run into one another, the leaf is 

 called decursivdy pinnate ^decursivl pinnatum), as in Sca- 

 biosa alpina. 



48. 



When the common leaf-stalk is divided in two parts, it is 

 said generally to be doubly compound (decompositum) ; and 

 when the division of the leaf-stalk is threefold, it is said to be 

 sup>er decompound {supra decompositum), as in Peucedanum 

 oflicinale. 



Doubly pinnated (bipinnatum), is a leaf, of which the com- 

 mon axis is again set forth with pinnated leaves, as in Athy- 

 rium Filix fccmina. The leaves of the first order are then 

 caWed pinna, oy Jbliola partialia ; the leaves of the second or- 

 der pinnulcE oxfoliola propria. 



Triply pinnate {triplicato-pinnatum or iripinnatuni), is a 

 leaf of which the common axis has a threefold subdivision. 



