66 



MORniOLOGT OF LEAVES AS FOLIAGE. [lesSON 9. 



Some Lupines have nine or eleven ; the Ilorsec-liestnut has seven, 

 the Sweet Buekeje more commonly five, tlie Clover three. A pin- 

 nate leaf often has only seven or live leaflets, as in the Wild Bean 

 or Groundnut; and in the Common Bean it has only three; in 



some rarer cases only two ; in 

 the Orange and Lemon only 

 one! The joint at the place 

 where the leaflet is united with 

 the petiole alone distinguishes 

 this last case from a simple 

 leaf.* 



170. The leaflets of a com- 

 pound leaf may be either entire 

 (as in Fig. 126-128), or ser- 

 rate, or lobed, cleft, parted, 

 ^. &c. : in fact, they may pre- 

 sent all the variations of simple 

 leaves, and the same terms 

 ^Zj^£^ equally apply to them. 

 Ni^^^^V 17 L When this division is 

 (£(L_ carried so far as to separate 

 ::>^x A^hat would be one leaflet into 

 t^\o, three, or several, the leaf 

 becomes doubly or twice com- 

 pound, either pinnateJy or pal- 

 '^^ matehj, as the case may be. 



For example, while some of the leaves of the Hone} -Locust are 

 simphj pinnate, that h, once pinnate, as in Fig. 128, the greater part 



* "Wlicn tlic botanist, in describing leaves, wislics to express tlic numl)er (f 

 leaflets, lie may use terms like tliesc : — 



Uiiifoliulate, for a eomj)Oun(l leaf of a single leaflet; from tlie Latin uiuim, ono, 

 and foliolum, leaflet. 



BifoUolalt', of two leaflets, from the Latin his, twice, nndjhliolmti, leaflet. 



Trifuliolatc (or termite), of three leaflets, as the Clover ; and so on. 



Wiien he would express in one phrase both the number of leaflets and the way 

 the leaf is compound, he writes : — 



Palmotcli/ hljbliolale, trlfollulalc, jiliirijoliokitc (of several leaflets), &c., or else 



Pinnatilij hi-, tri-, (jiiadri-, or pinri-fuliolalc (that is, of two, three, four, five, or 

 several leaflets), as the ^asc mav be. 



FIG. 130. A twice-pinnate (abruptly) leaf of the Honev-Lt>cnst, 



