1408 



POPULUS 



POPULUS 



the most striking and distinct tree that is suited to 

 planting in the North. As single specimens scattered 

 here and there in mixed plantings, or when seen over 



1908. Populus viminalis above and 

 P. angustifolia below (X M). 



or behind buildings, it may be most picturesque and 

 satisfactory; but the tendency is to plant it too freely. 

 Fig. 1907. The very fact that it is emphatic is the 

 reason why it should be planted sparingly when artistic 

 effects are desired. The catkins, particularly the 

 staminate ones, are usually attractive, as they appear 

 in early spring; but they are of short duration. In the 

 following account, the species are distinguished by 

 characters of foliage and habit, as these are the features 

 chiefly known to horticulturists. The following sketch 

 includes all the Poplars known to be offered by Ameri- 

 can nurserymen. Some of the Japanese and Siberian 

 forms, however, are in need of careful study. One of 

 the forms known as ".Japanese Poplar " may be referable 

 to P. suaveolens, Fisch., a species which is united with 

 P. balsamifera by some authors. P. suaveolens is 

 native to Amurland and Japan. For literature, see 

 Wesmacl, DC. Prodr. 1(3, pt. 2, pp. 323-331; Sargent, 

 Silva of North America, vol. 9 (quoted below as S.S.) ; 

 Bailey, Bull. 08, Cornell Exp. Sta., from which the fol- 

 lowing account of the cultivated species is adapted. 



INDEX. 

 deUoides, 5. 

 dilatata, 7. 

 Dudleyi, 1. 

 elegans, 7. 

 fastigiata. 7. 

 Oroica, 9, 10. 

 grandideiitiita, 10. 

 heterophyllji, 10. 

 lliiilsdiiica, 7. 

 intoriiifdiii, ;{. 

 If;ili<Ti, 7. 

 l;it,ifoli!i, .■?. 

 huirifolia, .'!, G. 

 lAiuUi'iirma. 1. 

 indcrojihiilla. ;i. 

 iiioiiiJifi'ra, .'). 

 nitjrsi, 7, 10. 



a'-uminata, 2. 

 alba, 12. 

 angustifolia, 2. 

 ariicntea, 12. 

 Athcnicnsis, 9. 

 balsamifera, 1, 3, 6. 

 Jifrealmsis, 6. 

 hetvUfolia, 7. 

 Bollcana, 12. 

 Canadensis, .'). 

 faiidicans, ;t. 

 canesfpiis, 7, 12 

 Carolina. r>. 

 Carnliniana, .'>. 

 Carolinr-nsis, .'i. 

 Certineiisis. G. 

 crisp a, 1. 



nivea, 12. 

 Nolestii, 3. 

 Ontariensis, 3. 

 Pannonica, 7. 

 Petrovski, 6. 

 PoUmica, 7. 

 pyramidalis 1 , ' 

 pyramidata, 7. 

 rotiindifolia, 11 

 salicifolia, 1. 

 Siliirica, 3. 

 Sioboldi, 11. 

 iSiiiionii, 4. 

 troiimla, H. 

 trciiniloidcs 

 viiniii.'ilis, 1 

 WoOsky, 3. 



A. Terminal buds large and long, glutinous-sticky and 



with a balsamic odor. — Balsam Poplars. 



B. Petioles terete or channelled {not flattened) . 



C. Branchlets sharply angled. 



1. vimin§,lis, Lodd. (P. //iwtiZei/fiwa, Booth. P.salici^ 

 folia, crispa, JJiidleyi, pyramiddlis suaveolens, Hort. 

 P. balsamifera, var. vimindlis, Loud.). Fig. 1908. 

 Small or medium-sized tree, of slender growth and with 

 a somewhat weeping habit when old: Ivs. broad-lanceo- 

 late, willow-like, finely serrate, often crinkled on the 

 margin. Asia. — This is very like the native Populus 

 angxisti folia, which it represents in Europe, but is 

 readily distinguished by its angled or furrowed stems, 

 and less tapering and crisped leaves which are conspic- 

 uously finely reticulated and whitened beneath. The 

 color of its foliage is grayish green, and in this respect 

 it affords a contrast to the native species. P. angusti- 

 folia seems to be rather the better tree of the two, al- 

 though the viminalis has a more striking appearance. 



CC. Branchlets terete (or sometimes grooved on strong- 

 growths). 

 D. Leaves long and narrow. 



2. angustifdlia, James. Fig. 1908. Small pyramidal 

 or conical tree (reaching CO ft. in the wild), with slen- 

 der twigs and small buds, and soft clear green foliage: 

 Ivs. small for the genus, lanceolate or ovate-lanceolate, 

 short-stalked, green on both surfaces, finely and evenly 

 serrate: catkins short, densely flowered : ovary some- 

 what 2-lobed. Interior region from Assiniboia to Ne- 

 braska and Arizona, and westward. S.S. 9:492.— Com- 

 mon street tree in parts of the West, and sometimes 

 planted in the East for ornament. — A related species of 

 similar ranges is P. acuminata, Rydberg, differing in 

 having long-petioled, rhomboid-lanceolate, acuminate 

 Ivs., which are serrate only at the middle. It will prob- 

 ably appear in cultivation. 



DD. Lvs. mostly broad-lanceolate to ovate or rounded. 



3. balsamifera, Linn. Balsam Poplar. Tacmahac. 

 Fig. 1909. Tall upright tree, with a narrow straight 

 top: lvs., thick and firm, erect, whitened beneath, usually 

 smaller than in most other Poplars of this group, in 

 shape ovate-lanceolate or oval, tapering towards the top 

 and sometimes at the base, finely and obtusely toothed, 

 dark green above, but whitish or rusty beneath: catkins 



9. 



1909. Populus balsamifera (X 3^). 



drooping, slender but rattier densely fid., appearing in 

 very early spring. Newfoundland to liritisli Columbia, 

 and southward into the northern tier of states; Asia. 



