LECT. X.) 



COMPOUND LEAVES. 



529 



directions of leaves which are 

 employed in forming the spe- 

 cific characters of plants. 



When the direction of a 

 leaf is nearly perpendicular, it 

 is said to be erect (erecta)*; 

 in which case it forms an acute 

 angle with the stem (see the 

 diagram, a. a.) : but if the angle 

 be so acute that the upper 

 disk of the leaf is closely pressed 

 to the surface of the stem or 

 the branch, it is then termed 

 adpressa. When the angle is 

 moderately acute only, or about 

 forty-five degrees (.), and the 

 surface of , the leaf, consequently, approaches the 

 line of the horizon, the direction is termed spread- 

 ing (patens sen patula); and horizontal (hori- 

 zontalis sen palentissima), when it spreads still 

 more, approximating to a right angle with the 

 stem or the branch when these are erect (c.), or 

 to ninety degrees in relation to the horizon. When 

 the feaf is spreading with a drooping apex (d.) 9 the 

 direction is termed nodding or inclined (cernua seu 

 inclinata): it is reflex (reflexa seu recurva), when 



* The term vertical is also employed by some writers, but 

 it is superfluous, the position of the most vertical leaf being 

 sufficiently described by the word erect. 



VOL. I. MM 



