INTRODUCTORY LESSONS. 



x.x 



bjise of the leaf. Fig. 40 represents a pinnately lobed leaf; Fig. 43, 

 paliiiately lobed. When leaves are deeply lobed, as in Figures 41 and 44, 

 they are said to be Parted. Divided leaves are cut quite to the midrib if 

 pinnately divided, or to the end of the petiole when palmately divided. 

 Cleft leaves have the sinuses between the lobes sharp as in Fig. 38. When 

 leaves are pinnately cleft about half way to the midrib they are said to be 

 Piiinatifid. If the lobes are pinnatifid it is described as Blpinnaiifid. It 

 is common to give the number of lobes in the descriptive phrase, as pin- 

 nately nine-lobed (Fig. 40); pinnately eleven-parted (Fig. 41); palmately 

 live-lobed (Fig. 43); palmately five-parted (Fig. 44). 



Compound Leaves have distinctly separate leaflets usually jointed 

 to a common petiole, just as simple leaves are jointed to the stem. A leaf 

 is Pinnate^ when the leaflets grow 

 along opposite sides of the petiole 

 (Fig. 42); Palmate , if they all grow 

 from the end of the petiole (Fig. 

 46). Fig. 45 represents 2i. pinnately 

 S-foliolate leaf; Fig. 46, palmately 

 o-fuliolate. When there is no odd 

 leaflet at the end the leaf is ah- 

 r aptly pinnate. Leaves may be 

 twice, thrice^ etc., compound, that 

 is, the leaflets may be compound 

 a? in some acacias. 



Bracts are leaves among flow- 

 ers, or small undeveloped leaves 

 anywhere on the stem. 



Stipules may be adnate to 

 the base of the petiole, as in the 

 rose and clover (Figures 45, 46); 

 some plants of the Buckwheat Family the stipules form a sheath surround- 

 ing the stem at the base of the petiole. Do not mistake the first leaves 

 a growing axillary bud for stipules. 



45. Pinnately 3-foliolate leaf of Bur-clover, -with 

 email stipules. 46. I'almately or digitately 3-foliolat6 

 leaf of a true clover, the broad adnate stipules lacerate. 



they may grow on the stem; or, as in 



of 



Venation of 



to be Netted-veined or 



Leaves. All the leaves thus far described are said 

 Pirticulaled, because their skeletons of wood fiber 



