POSITION OF LEAVES 



37 



Fig. ?!. 



Tripinnate, Fig. 71, (three times 

 winged,) when the common petiole 

 has bipinnate leaves on each side. 

 The figure shows a tripinnate leaf 

 ending with an odd one. Ex. An- 

 gelica tree, (Aralia spinosa.) 



With respect to the position of the leaf the following dis- 

 tinctions are made, viz. 



Erect, Fig. 72, (upright,) when the leaf forms 

 a very acute angle with the stem. Ex. pointed 

 Rush, (Juncus articulatus,) Cat's-tail, (Typha 

 latifolia.) 



Horizontal, Fig. 73, (spreading,) 

 when the leaves are parallel with 

 the horizon, and form right angles 

 with the stem. Ex. Wild lettuce. 

 (Lactuca sylvestris,) Boneset, (Eupa- 

 torium perfoliatum.) 



Reclined, Fig. 74, (reflected,) when the 

 apex falls down so as to be lower than the 

 insertion of the petiole. Ex. Grass leaved 

 groundsel, (Senecio reclinans.) 



Fig. 73. 



When is a leaf said to be tripinnate ? With respect to its position, 

 when to be erect ? When horizontal ? When recline'd ? 

 4 



