7& THE POPLAR. 



serves, is placed at a right angle with the leaf, 

 being thus peculiarly fitted to receive the impulse 

 of every wind that blows. This stalk is furnished 

 with three strong nerves, placed parallel, and acting 

 in unison with each other ; but towards the base 

 the stalk becomes round, and then the nerves assume 

 a triangular form, and constitute three distinct 

 supports and counteractions to each other's motions. 

 I know no petiole with a similar conformation, or 

 better calculated for the vibration of a leaf. The 

 leaf-stalks of plants are very curious constructions ; 

 and the nerves and vessels contained in them, which 

 are the vehicles of a large portion of that nourish- 

 ment which plants receive through their foliage 

 from the air, seem in general differently placed, and 

 fitted for variety of operation. The poplar is a tree 

 that occasions at times a good deal of trouble in 

 our pasture lands, by the tendency which it has to 

 extend its roots and throw out suckers. Three or 

 four of this species in a hedge-row, bounding a 

 meadow in my occupation, oblige me every year 

 that the field is mowed, by their profligacy, to send 

 a man wijth his stockaxe to remove their numerous 

 offspring, a mere temporary expedient, tending 

 rather to increase the complaint, as eradication by 

 trenching with the spade can alone effectually check 

 the encroachments of runners so tenacious of life, 

 and rapid in growth. 



The dyer's broom (genista tinctoria) abounds 

 with us, and becomes a perfect incumbrance in our 

 clay land pastures. It is seldom eaten by cattle, 



