96 



LUSSOIfS WITH PLANTS 



similar makeup. Lobed leaves are those in which the divisions are 

 uot more than half the depth of the blade; cleft leaves have the divi- 

 sions extending deeper than the middle ; parted is used for still deeper 

 sections; and divided for those leaves which are cut nearly or quite 

 to the midrib, but in which the parts (or divisions or segments) are 

 not distinct enough to be called leaflets. Lobed and cleft leaves are 

 designated in botanical phrase as bifid, trifid, quadrifid, multifld, 

 etc. ; parted and divided leaves are designated as bisect, trisect, etc. 

 Pinnately-lobed leaves are pinnatifid ; . pinnately-di- 

 vided leaves are pinnatisect (but there are no cor- 

 responding palmatifid and palmatisect in general use). 

 Compound leaves which are cut and divided very 

 much and more or less indefinitely (as in Fig. 87) 

 are said to be dissected, whether pinnate or pal- 

 mate. 



Suggestions. — The venation of a, leaf (or petal) is 

 the arrangement and other features of the veins or 

 ribs. Let the pupil collect abundantly of leaves (and 

 indiscriminately, if he choose), and match the vena- 

 tion in them. Possibly he may find his pencil useful 

 in recording and interpreting the differences. 



XVIII. DISGUISES OF LEAVES 



105. We have noticed how varied and 

 disguised the parts of leaves may be, 

 upon occasion. Fig. 92 is a sprig of 

 a common weed, the veronica or speed- 

 well. The normal leaves are shown 

 at the base ; but they become grad- 



shoot of speed- ually Smaller as the top is approached, 

 and finally are little more than scales. 



Such gradations are very common, especially in 



Fig. 92. 



