THK LEAF. 



61 



common Oak-leaf; lyrate, apinnatifid or pinnatipartite leaf, with the end 

 lobe much larger than the ivst (Jig. 5-'>); runcinate, a /yrote or simply 

 pinnated leaf with the points of the lateral lobes turned towards the base, 

 as in the Dandelion. When the incisions are deep, but very irregular in 

 size and form, the term laciniate is sometimes employed. 



When the ribs have the palmate arrangement, similar terms are sub- 

 joined to the prolix pahni- or palniati-, or palniitid (tig. i>4), palm i sect 

 (tig. iH>). and palmipartite (tig. t>.">\ according to the depth of the divi- 

 sions. A special modification of this type occurs not uuirequently, when 

 the lower or outer ribs, and consequently the basilar lobes, turn back more 

 or less towards the petiole ; such leaves are generally deeply cut ; but the 

 general prolix pedati- may be used in the words pedatifid, pedatisect, or 

 pedatipartite (tig. 97), according to the rule given above. Such leaves 

 may be compared to sympodial ramifications; the central lobe is the 

 primary one from which on either side lobes of the second degree are 

 formed : these produce tertiary lobes, and so on, but always on one side 

 only, as in some forms of definite ramification. 



Fig. 96. 



Fig. 97. 



A ivilmis.vt leaf, the segments 

 oblonR-obovate serrated. 



A pedatipartite leaf, the 

 segments lanceolate. 



The bilobed, tt-tlobed, quinquelobed, and similar forms are usually refer- 

 able to the palmate type, and should be more definitely named if they 

 occur in a genus where the leaves exhibit many of these forms, in a con- 

 stant manner ; if the leaves are inconstant in the depth of the divisions, 

 those more general names are preferable. 



Simple leaves divided on the feathered plan exhibit also more compli- 

 cated conditions. The primary lobes of a pinnately cut leaf may be sub- 

 divided again in the same manner, and the secondary lobes again into ter- 

 tiary lobes. These are named on the same principles, bipinnati-,tripinnati- 

 -fi',1, -mrf, or -partite, according to the degree of division of the last set of 

 io!><;*, i. e. of the secondary lobes ofbipinnatifid (fig. 98) and the tertiary of 

 tripinnatitid. When the leaves are subdivided a fourth fcme, or even 

 where tripinnatitect leaves have JUifonn segmetds, the term dissected is 

 usually employed. 



It must be borne in mind that the terms above defined are applied in a 

 similar manner to the leaflets of compound leaves, next to be described, 

 being subjoined in description to the terms which define the plan and 



