BLACK POPLAR 221 



The buds are sometimes slightly triangular in section, 

 polished brown, resinous ; twigs long and slender, grey- 

 ish green to tawny or reddish brown. 



A A Buds not ovoid, more conical 

 and taper-pointed, appressedor 

 directed outwards, not incurved, 

 twigs slightly angidar at the 

 tips. 



P. nigra, L. Black Poplar (Fig. 113). The flower- 

 buds are larger and tend to be recurved at the apex. All 

 are conical, or cylindroid-conic with tapering sharp points, 

 and often very viscid. The terminal bud may be much 

 the larger, and expose 7 8 or more scales, the laterals 

 sometimes very small. Lenticels scattered. Leaf-scars 

 as in P. tremula, or narrower and inclined to crescentic, 

 on rather prominent leaf-bases. 



Twigs shining yellow or yellow-tawny and glabrous, 

 passing to olive-grey or darker grey, usually round below 

 and devoid of corky ridges, but slightly angular above, or 

 striate. Terminal and flowering buds much larger than 

 the rest, especially on the dwarf-shoots. The variety 

 pyramidalis, Lombardy Poplar, Pyramidal Poplar, differs 

 in nothing except the more vertical direction of the lateral 

 twigs. The buds are usually small and appressed. 



The bud-scales are stipules, but broader, more shortly 

 pointed and more leathery than the ordinary stipules. 

 The outermost pairs have no traces of leaves between, 

 but as we go in at about the 7th to 9th pair in the 

 large terminal buds they become narrower and more 

 delicate and each pair has its corresponding, involute, leaf 

 (Fig. 27). 



Each lateral bud has one anterior scale surrounding 

 the bud, but open on the posterior side. This is followed 



