Plex.^on, 4. SALICINiE. Y. Populus. 243 



b. Turions smooth, laid; stamens 12 t<>\Q. ^^Egirus. 



4. Populus nigra. Black poplar. 



Leaves deltoid, pointed, serrate, both sides smooth ; pe- 

 tiole short; branches T^atuloxxs. 



Populus nigra, Rail Syn. 446, 1 ; Ger. em. 1486; Lin. S. P. 1464. 



Watery places ; tree ; March. 



Tree tall, smooth; leaves dark green; petiole half as 

 long as the leaves; a me/i^i smooth. 



Fam. V. 5. BETULIDE^. 



FloLvers monoicous, amentaceous. — Male, Perigonium 

 none, or 4-cut; stame?is 4 or 12, inserted on the scales of 

 the ament ; anthers 2-celled. — Female, Perigonium 0; 

 ovary free, 2-celled; stigmata 2 to 4, terminal; niiculaP 1 

 or 2-celled, in the scales of a cone ; perisperm ; corculum 

 straight, flat ; radicle above. — Tree or shrub ; leaves alter- 

 nate, annual, when young having 2 stipules at the base. 



Stamens 12 ; nucula P edged Betula. 8. 



Stamens 4 ; nucula P ovate, naked Alnus. 9. 



I. 8. BETULA. Pliny. Birch, 



Ament long, cylindrical. — Male. Scales in threes ; middle 

 scale stamen-bearing; perigonium 0; stamens 12. — Female. 

 Scales deciduous, 3-lobed at the tip, 2 or 3-flowered at 

 the base; styles 2; ovary compressed, 2-celled, 1 abortive; 

 nucida heartshape, with a membranaceous edge. 



1. Betida alba. White birch. 



Leaves deltoid, acute, doubly serrate, smooth; lateral 

 lobes of the scales of the cone rounded. 



Betula, Rail Syn. 443 ; Ger. em. 1478. 

 Betula alba, Lin. S. P. 1393. 



Woods and hedges ; tree ; April and May. 



Bark white, epidermis peeling off; leaves petiolate, be- 

 neath pubescent; co?ie peduncled, drooping; scales cylin- 

 drical ; twigs and buds blackish. — Bark used anciently for 

 writing on ; leaves applied outwardly and taken internally 

 in dropsy, and other diseases, also used to dye yellow; 

 twigs used for brooms, and for correcting children, on ac- 

 count of their toughness ; juice obtained by piercing the 

 tree under a large arm, nearly through to the bark on the 



k2 



