50 PRACTICAL BOTANY, 



degrees of division, illustrating the gradual transition of 

 leaves from simple to compound in all degrees. 



Again, we distinguish simply and repeatedhj compoiitid 

 leaves. 



101, Leaves simply compound, both of the pinnate 

 and tlie palmate sort, receive different names from the 

 number of their leaflets. 



Jn pinnate leaves the number of leaflets varies from 

 three (or i*arely one) to sixty, and upward. When a pin- 

 nate leaf has tliree leaflets, it is said to be trifoliolate, or 

 ternate; when two, hinate. When we find among three- 

 foliolate leaves one with only one leaflet, as in Desmo- 

 diurn^ llhynchosia, and Baptlsia^ we must, in theory, re- 

 gard such a leaf as a compound, since its single leaflet is 

 articulated to the petiole. 



When a pinnate leaf has an uneven number of leaflets, 

 the odd one being borne on the very tip of the common 

 petiole, it is said to be odd-pinnate^ or unequally-pinnate ; 

 and when it has an even number, it is equally- or ah- 

 ruptly-pinnate. The latter may bear a tendril at the end, 

 in place of an odd leaflet, as in the Vetches and in the 

 Pea. (PhIL, 8.) 



A lyrate leaf, becoming compound, is said to be lyrately- 

 pinnate. 



Pinnate leaves with smaller leaflets irregularly inter- 

 mixed with larger ones, as in Agrimonia Eupatoria^ are 

 said to be interruptedly -pinnate. 



Palmate leaves may be ternate^ quinate, septinate, etc. 

 — that is, they may have three, five, seven, etc., leaflets 

 springing together from the top of the common petiole. 

 In PI. II., 6, we have a septinate leaf. A palmately three- 

 foliolate leaf must not be mistaken for a three-foliolate 

 pinnate one, which has the odd leaflet raised above the 



