23 



Leaves .spreading, flat, in adult trees ovate, or roimdish 

 ovate, shortly acuminate, sometimes slightly cordate, not 

 rarely somewhat cuneate at the base, five-nerved, often with 

 an additional pair of slender nerves, closely and slightly crc- 

 nated ; crenatures covering very minute glands ; above brio-lit 

 green, beneath whiter, minutely reticulated. 



Leaves ou young trees in a less degree, but by no means 

 shortly petiolated, ovate, oblong. 



N.B. Found planted about St. Petcrsburgh and Moscow, 

 and supposed to be of foreign introduction. " Probably Ame- 

 rican. 



34. PopuLus laurifolia, Ledeb. fl. Alt. vol. iv .p. 2.97, Sfc. 

 t. Aid. P. balsamifera, Pall.flor. Moss, t. Al.fg. 13. Spach. 

 I. c. p. 33. 



Tree tall, pyramidal, bright green ; branches very angular, 

 grey, in adult trees stoutish. Buds swollen, yielding a balsam 

 smelling of storax. 



Stipules erect, mucronate, balsamiferous. 



Petioles at the lower end roundish, compressed towards 

 the apex, with a very narrow furrow, short, those of the 

 cordate leaves generally shorter, and of the oblong-lanceolate 

 leaves larger ; from half to six times shorter than the blade of 

 the leaves. 



Leaves flat, sometimes oblong, even, lanceolate-oblong, and 

 attenuate at the base, sometimes ovate-oblong, rounded or 

 cordate at the base, acuminate, acute, triple-nerved, often with 

 an additional pair of nervures at the sides, closely and minutely 

 crenated ; crenatures remarkably glandular ; bright green, be- 

 neath paler, not opaque, reticulated, tolerably firm. Third rib 

 but little dilated towards the insertion of the petiole. Leaves 

 of young trees stronger and often undulated. 



M.B. A specimen brought by Mardovkin from the Altai 

 regions had perfectly and broadly ovate leaves (almost like 

 Hibiscus syriacus), five-nerved, coarsely crenated. It was 

 first introduced by Ledebour from that country. It stands 

 the hardest frost, 



35. PopuLUS suaveolens, Fisch. P. balsamifera, Pall.jior. 

 Ross. ^.61. principal figures and letters, Sfc. 



Tree with us middle sized pyramidal, in Dahuria, according 

 to Pallas, a shrub, with a greyish green aspect; branches 



