POPULUS 



POPULUS 



1411 



rarely seen, even in cultivated grounds. It is some- 

 times spontaneous in the East. The tree known in the 

 West as Populus betulifoUa is only a robust form of 

 the European P. nigra. Variable in cult, and grown in 

 European collections under a variety of names. With 

 the exception of var. Itiilica, these forms are little 

 known in this country. 



1916. Populus tremuloides (X Vs). 



Var. ^leg'ans, Bailey (P. elegans of nurserymen), is 

 a tree of pronounced stricter pyramidal habit, but con- 

 siderably broader than the Lombardy Poplar: foliage 

 small and light-colored and very versatile in a breeze, 

 with a handsome reddish tint to the leaf-stalks and 

 young shoots. It is worth growing in every well-kept 

 place, especially if placed against a planting of heavier 

 foliage. Populus canescens of some American nur- 

 serymen is very like this, although it has less color 

 and brightness. 



Var. Italica, Du Roi (var. pijramiddlls, Spach. P. 

 Itdlica, Moench. P. dilatdta, Ait. P. fastigidta, Desf. 

 P.pyramiddlis, Rozier. P.pyrdinidiita, P. Panndnica, 

 P. Polbnica, Hort. ). Lombardy or Italian Poplar. 

 Figs. 1907, 1914. Differs from the typical Black Poplar 

 (P. nigra) in its tall, narrow growth, glabrous young 

 shoots, a confirmed habit of suekering from the root 

 and generally a more tapering base to the leaves. It is 

 one of the characteristic trees of parts of Italy, and it 

 is from one of the Italian provinces, Lombardy, that 

 its common name is derived. The tree is probably na- 

 tive in Asia, however. With age, the Lombardy Pop- 

 lar becomes one of the most striking and picturesque 

 of trees, particularly when some of the sprouts are 

 allowed to grow about the old stock, as in Fig. 1907. In 

 the northernmost states it is not long-lived. 



1917. Populus grandidentata (X 34). 



AA. Terminal buds relatireli/ small, not glutinous, 



often pxiheseent. Aspens and White Poplars. 

 B. Mature Ivs. ustially green, greenish or brown be- 

 neath. 

 8. tr6mula, Linn. European Aspen. Fig. 1915. 

 Open headed, light-leaved tree, becoming 50-60 ft. tall: 

 Ivs. small and thin, round-oval, more or less whitened 

 beneath when young, bordered with deep and rounded 



incurved teeth; the leafstalks long, slender and flat- 

 tened, giving a restless motion to the foliage: leaf-buds 

 small. Widely distributed in Europe and Asia, in this 

 country known chiefly in its weeping form (var. pen- 

 dida}. — The weeping form of the European Aspen is 

 perhaps the best weeping tree amongst the Poplars. 

 The spray is light, airy and fountain-like, quite unlike 

 the more common weeping forms of our native Populus 

 grandidentata, which present a stiff, angular form, a 

 combination that is rarely pleasing. A characteristic 

 feature of this tree is the profusion of its very long 

 catkins that appear in earliest spring, even before our 

 native I'oplars are in bloom. The staminate or male 

 catkins are particularly pleasing, and planters should 

 select that sex, if possible. 



9. tremuloides, Michx. {P. Atheniinsis and Grleca, 

 Hort.). American Aspen. Figs. 1906, 1916. Very like 

 P. tremnla, but the Ivs. are usually less circular and 

 more abruptly acuminate, the margins are small-crenate 

 rather than deeply toothed, and the Ivs. are green on 

 the under side. Generally distributed in North America 

 north of Pennsylvania and Kentucky, and extending to 

 Mexico in the mountains. S.S. 9:487. — One of the first 

 trees to spring up in clearings. The bark of the young 

 trees is whitish gray, rendering the saplings very con- 

 spicuous in a coppice. In woods the tree is said some- 

 times to reach a height of 100 ft , but it is usually much 

 smaller than this. There appear to be no horticultural 

 varieties. 



10. gn^andident^ta, Michx. {P. Grwca plndula, P. 

 n'igra pendula and Parasol de St. Julien of nursery- 

 men). Large-toothed 

 Aspen. Fig. 1917. Tall, 

 straight tree, becoming 

 75 ft. high, known in 

 cultivation in various 

 weeping forms. Distin- 

 guished from P. trem- 

 ula by much larger and 

 thicker Ivs., which are 

 bluish or rusty white be- 

 neath, more ovate in out- 

 line, with larger and 

 more spreading teeth, 

 stouter leaf-stalks and 

 larger leaf-buds. Nova 

 Scotia to Minn, and 

 Tenn. S. S. 9:488.- In 

 its normal or erect form 

 it is rarely cultivated, 

 but the weeping kinds, 

 under a variety of names, 

 are frequently seen. Most, and perhaps all, of these 

 varieties originated in Europe, where the tree, like the 

 Cottonwood and the common Aspen, were early intro- 

 duced. The habit of the tree is too stiff and the foli- 

 age rather too heavj^ to make the best weeping subjects, 

 however. One of the best of these weeping forms is 

 that known as Parasol de St. Julien. The winter twigs 

 of the weeping varieties have a characteristic weak or 

 zigzag growth.— P. heterophylla, Linn., a tall tree of 

 tlie eastern U. S., may be in cult., although it does not 

 appear in trade lists. It has cordate-ovate, obtuse, 

 crenate Ivs., with terete petioles, the young parts and 

 the Ivs. white-tomentose. It is mostly an inhabitant of 

 swamps. 



11. Sidboldii, Miq. {P. rotundifolia. Hort.) Fig. 1918. 

 Tree, 20-.S0 ft., of spreading habit, with rather dark and 

 heavj' foliage: Ivs. large, round-ovate, with a short tri- 

 angular subacute apex, nearly or quite truncate at the 

 base, dentate-serrate, with shallow incurved teeth, more 

 or less whitened beneath. Japan. — Hardy in western 

 New York. 



BB. Mature Ivs. usxially n-hite tomentose beneath, at 

 least in the cultivated forms. 



12. dlba, Linn. White Poplar. Abele. Large, much- 

 branched tree, with whitish bark on the young branches: 

 Ivs. much like those of Populus grandidentata, but 

 smaller, usually thicker and more angular, the under 

 surface — especially early in the season — woolly white. 

 Eu. and Asia. — The typical form ot Populus alba is less 



1918. PoDulus Sieboldii(X J4). 



