380 APPENDIX. 



DO tree could be substituted that would flourish so well. This 

 road is built with marsh mud and gravel, and raised so high above 

 the marsh that the suckers will not interfere with the adjoining 

 land. These long lines of Abeles are very beautiful, when the 

 leaves are agitated by the wind, and the silvery white of the 

 under side is more fully contrasted with the green of the upper side. 

 Populus tremuliformis. American Aspen, or Trembling 

 Poplar. This is a well-known, small, graceful tree of our forests, 

 remarkable for the continual agitation of its leaves by the slight- 

 est breath of wind. It resembles the P. tremula, or Aspen Pop- 

 lar, of Great Britain, in this respect, as well as in its general ap- 

 pearance and to which Walter Scott alludes in his lines : 



" 0, woman ! in our hours of ease 

 Uncertain, coy, and hard to please, 

 And variable as the shade 

 By the light quivering Aspen made; 

 When pain or sickness rends the brow, 

 A ministering angel thou." 



The Weeping Poplar has been introduced from Europe, 

 probably a variety of P. tremvla, and is a desirable orna- 

 mental tree. 



The Balm of Gilead and Lombardy Poplar were in great re- 

 pute fifty years ago, but have had their day, and are generally 

 rejected at the present time.* 



PRINOS. 



P. verticillatus. Black Alder. This indigenous shrub, so 

 ornamental in low grounds and swamps in autumn, was unnoticed 

 in the first edition ; but it is worthy, not only of a notice, but also 

 of a place in every collection of shrubs. " It is a handsome shrub, 

 five or six rarely ten or twelve feet high, with crowded 

 branches and leaves, conspicuous for its bunches of axillary bios- 



* There is also a popular tradition connected with the Poplar, namely, that 

 the Cross of the Saviour was made of its wood; and that neither its foliage noi 

 its trunk has since been seen, while growing, in a quiescent state. 



