POPULUS 



S.S. 9:490.— The native form is occasionally seen about 

 farm buildings and roadsides, where it makes a durable 

 and interesting tree; but it is rather too stiff for the 

 pleasantest effects and too narrow for the best shade. 

 The dull whiteness of the under side of the leaves af- 



1910. Populus 



fords a pleasant variety and contrast in its foliage, and 

 the fragrance of the resinous buds in spring is agreeable 

 to most persons. It is a desirable tree for occasional 

 planting, but, like the Lorabardy, it generally appears 

 to best advantage when placed amongst other trees. It is 

 a hardier tree than the Lombardy, and does not run 

 quickly to such extravagant heights. In cultivation 

 from Russian sources, it is known as Nos. 10 and 26 

 Voronesh and 32 Riga. The Balsam Poplar is probably 

 the most variable of Poplars. In cultivation in this 

 country it is represented by at least three well-marked 

 botanical varieties, differing from the species and from 

 each other in the habit of growth, shape and color of 

 leaves and character of twigs. 



Var. intermedia, Loudon [P. lauritdlin of American 

 horticulturists, not of botanists. P. Sibirica pyrami- 

 diilis, Hort.). A comparatively slow-growing tree of 

 close, upright habit: Ivs. very thick and hard, finely ser- 

 rate, oval in outline, and prominently whitened beneath, 

 commonly rather small for this group: twigs hard and 

 cylindrical. N. Asia. — It is considered to be a valuable 

 tree for hot and dry interior climates; and it also has 

 distinct merit for ornamental planting. It eventually 

 becomes a large tree. The Popuhis hiurifoUa and P. 

 SihirU-a pi/ramidalis of American nurserymen are, 

 apparently, only minor variations of this type. These 

 trees are amongst the recent introductions of Russian 



Popla 



Hort. 



latifdUa, Loudon (P. IVol/sli 

 . Fig. 1910. Includes forms ■ 



nd P. Wdbskij, 

 h ovate or cor- 

 -ovate rather blunt-pointed leaves, cylindrical twigs 

 (or slightly ridged on strong shoots) and the general 

 habit of the Balsam Poplar. Asia. -The Ivs. are usually 

 large and thick, shining green above and dull white be- 

 neath, in shape and texture somewhat like the next 



Populus balsamifera, var. candicans ( 



variety. The Nolestii Poplar is now sold by eastern 

 nurserymen as an ornamental tree. Its strong habit and 

 dark foliage adapt it admirably to planting near the rear 

 borders of grounds. The Wobsky Poplar is one of the 

 recent Russian introductions, with somewhat the habit 



POPULUS 1409 



of a cherry tree, and is much prized in the Northwest. 

 The Rasumovskoe Poplar appears to be of the same type. 

 Var. ctindicans, Gray {P. candicans. Ait. P. Ontari- 

 t^iisis and P. 7nacrophijlla, Hort.). Balm op Gilead. 

 Fig. 1911. Strong-growing spreading native tree, fre- 

 quently planted, and esteemed for its vigor and hardi- 

 ness and the resinous fragrance of its large buds in 

 spring-time: Ivs. broad and heart-shaped, green above 

 and veiny and rusty-white beneath, the leaf-stalk usu- 

 ally hairy and somewhat flattened. New Brunswick to 

 N. J. and W. to Minn. S.S. 9:491. Gn. 29, pp. 125, 126. 

 — It is very different from the Balsam Poplar in method 

 of growth, as it has none of the pyramidal or spire-like 

 tendency of that species, but usually makes a broad and 

 irregularly spreading top. While the tree is common in 

 cult., it is rare wild. In the early days, however, it was 

 found in very large trees in Jlichigan and other western 

 states, and was used for sawing timber; and small iso- 

 lated natural groves of it are still to be seen. The 

 Balm of Gilead makes a good street tree, and is perhaps 

 the best of the Poplars for shade. Well-grown trees 

 have the darkest and richest foliage of any common 

 Poplar, and this character makes the tree valuable in 

 heavy groups about the borders of a place. The top is 

 liable to become open and broken with age, however. 



1912. Populus deltoides below. P. laurifolia above (X M) 



and the tree often sprouts profusely. It is not well 

 adapted to smoky and dusty locations, as it soon be- 

 comes grimy. Probably a good species. 



4. Slmonii, Carr. A strong, strict tree with Ivs. dif- 

 fering from those of the Balm of Gilead in having a 

 rounded or tapering base and much finer teeth, but 

 otherwise they are much alike. The shoots are reddish 

 brown and spotted, and deeply grooved. China. — Int. 

 into France about 1861 by M. E. Simon, and somewhat 

 planted in this country. Some authors consider this to 

 be only a form of P. balsamifera, and if the Balm of 

 Gilead is to be regarded as a form of that species, per- 

 haps this should be. For horticultural purposes, how- 

 ever, it seems to be distinct. It has been planted as far 

 north as Manitoba with entire success. It is a very rapid 

 grower. Useful where quick-growing wind-breaks are 

 desired. 



BB. Petioles usually distinctly flattened, so that the 



leaves turn easily in the wind. 



c. Leaves large, for the most part as long as, or 



longer than, broad. 



5. deltoides. Marsh. (P. monilifera, Ait. P. Cana- 

 densis, Moench). Cottonwood. Fig. 1912. Becoming 

 a large, much-branched picturesque tree, with deeply 

 furrowed gray-brown bark: Ivs. large, triangular-ovate, 

 mostly truncate or nearly straight on the base, ab- 

 ruptly acuminate, coarsely crenate-dentate but the mar- 

 gin plane or flat, the petiole long, much flattened near 



