rOKMS OF SIMPLE LEAVES. 87 



to about the middle and are broad ; or pectinate (pecten, a comb), wlieii 

 they are narrow ; or pinnatipartite, when the divisions extend nearly 

 to the midrib. These primary divisions may be again subdivided in a 

 similar manner, and thus a feather-veined leaf will become bipinnatifid 

 (fig. 153), OT bipinnatipartite ; and still further subdivisions give origin 

 to tripinnatifid and laciniated leaves. If the divisions of a pinnatifid 

 leaf are more or less triangular, and are pointed downwards towards 

 the base, the extremity of the leaf being undivided and triangular, the 

 leaf is runcinate (runcina, a large saw), as in the Dandelion. When 

 the apex consists of a large rounded lobe, and the divisions, which are 

 also more or less rounded, become gradually smaller towards the base 

 (fig. 154), as in Barbarea, the leaf is called lyrate, from its resemblance 

 to an ancient lyre. Under the term lyrate some include compound 

 pinnate leaves in which the several pinnae are united at the apex of 

 the leaf, and the others become gradually smaller towards the base. 

 When there is a concavity on each side of a leaf, so as to make it 

 resemble a violin, as in Eumex pulcher (fig. 155), it is called panduri- 

 form (^ranSoDga, a fiddle). 



The same kinds of divisions taking place in a simple leaf with 

 radiating venation, give origin to the terms lobed, cleft, and partite 

 (figs. 161, 189). When the divisions extend about half-way through 

 the leaves, they may be three-lobed, five-lobed, semn-lobed, many-lobed ; 

 or, trifid, quinquefid, septemfd, multifid, according to the number of 

 divisions. The name of palmate, or pahnatifid (fig. 159), is the 

 general term applied to leaves with radiating venation, in which 

 there are several lobes united by a broad expansion of parenchyma, 

 like the palm of the hand, as in Passion-flower and Eheum palmatum. 

 The divisions of leaves with radiating venation may extend to near 

 the base of the leaf, and the names bipartite, tripartite, quinque- 

 partite or digitipartite, and septempartite, are given according to the 

 number of the partitions, two, three, five, or seven. In Drosera 

 dichotoma (fig. 88), bipartite and tripartite leaves are seen. The 

 term dissected js applied to leaves with radiating venation, having 

 numerous narrow divisions, as in Geranium dissectum. When in a 

 radiating leaf there are three primary partitions and two lateral ones, 

 spreading and forming divisions on their inner margin only, as in 

 Helleborus (fig. 185), the leaf is called pedate or pedatifd (pes, a foot), 

 from a fancied resemblance to the claw of a bird. 



In all the instances already alluded to the leaves have been 

 considered as flat expansions, in which the ribs or veins spread out 

 on the same planes with the stalk. In some cases, however, the veins 

 spread at right angles to the stalk. If they do so equally on all sides, 

 and are united by parenchyma, so that the stalk occupies the centre 

 (fig. 160), the leaf becomes orbicular (orbis, a circle), as in Hydrocotyle ; 

 if unequally, so that the stalk is not in the centre, the leaf is peltate 



