2756 



POPULUS 



POPULUS 



Asia. The typical form of P. alba is less grown here 

 than the varieties with lobed and very white-bottomed 

 (and sometimes variegated) Ivs. In old places and yards 

 it is sometimes found, but var. nivea and in newer 

 grounds var. pyramidalis are more frequent. Var. 

 globdsa, Spaeth. Dense small tree or shrub, oval in 

 outline of head: Ivs. small, deltoid-cordate, slightly 

 lobed, gray beneath and pinkish when young. Of 

 horticultural origin. Var. pendula, Loud. Branchlets 

 drooping. Var. Richardii, Hort. Lvs. yellow on upper 

 surface. 



Var. nivea, Wesm. (P. nivea, Willd. P. argentea, 

 Hort. P. arembergiana, Hort.). This is the commonest 

 form of white poplar in this country. It is known by the 



3128. Populus tremula var. psendograndidentata. ( X W 



snow-white under surfaces of its foliage and the 3- or 

 5-lobed maple-like Ivs. It is far too frequent about 

 old yards, where its inveterate brood of suckers make 

 it a perpetual nuisance. It is sometimes called "silver 

 maple," from the resemblance of its foliage to that of 

 the maple. As a street tree in cities it is particularly 

 offensive, for the cottony covering of the under side of 

 the leaves and of the shoots holds soot and dust, and it 

 looks repulsively dirty. Useful for foliage effects in 

 large plantings. 



Var. subintegeirima, Lange (P. subintegerrima, 

 Dode. P. ' monticola, Brandegee. P. Brdndegeei, 

 Schneid.). Lvs. coriaceous, those on the long shoots 

 ovate or orbicular, somewhat cordate or cuneate at 

 base, nearly entire to somewhat toothed, white under- 

 neath; those on short shoots nearly circular, entire or 

 slightly sinuate, gray underneath. Spain, N. Afr. 

 Early intro. into Mex. and apparently naturalized in 

 Low. Calif. G.F. 4:330; 6:190; 7:313 (descs.). 



Var. pyramidalis, Bunge (P. Bolleana, Carr. P. 

 alba var. Bolleana, Lauche). BOLLE'S POPLAR. Fig. 

 3126. A very tall narrow-topped tree, with cottony 

 Ivs. rather more deeply lobed (palmately 3-5-lobed) 

 than those of var. nivea, those on the short shoots circu- 

 lar, coarsely triangular-toothed. The tree was intro. 

 into Eu. from Asia in 1872 from Turkestan, and it was 

 named for Dr. C. Bolle, an arboriculturist. It bears 

 about the same relation to P. alba that the Lombardy 

 poplar bears to P. nigra. Its fastigiate habit, combined 

 with the white foliage and shoots, makes it a most 

 emphatic tree, and there is great danger of planting it 

 too freely. It is said to be much attacked by borers. 



2. canescens, Smith (P. dlba var. canescens, Ait. P. 

 megaleuce, Dode. P. hybrida, Reichb. P. Steiniana, 

 Bornm.). GRAY POPLAR. Fig. 3126. Lvs. broad or 

 nearly circular in general outline, prominently notched 

 but not lobed, the under surfaces and the young shoots 

 very gray-woolly, those on young or long shoots ovate- 

 deltoid, cordate and acute, grayish tomentose beneath, 

 the margin few-toothed and ciliate; those on short 

 shoots nearly circular or broad-ovate, subcordate and 

 obtuse, not ciliate, the lower surface light green. Var. 

 pendula, Hort., is a fine form with pendulous 



branches. This tree is met with occasionally. Its 

 horticultural value is not greatly different from that of 

 P. alba var. nivea. According to Elwes & Henry, P. 

 Bogueana, Dode, is a vigorous form of this species in 

 which the Ivs. on long shoots are 5 in. or more in length 

 and breadth; appears to be sold by some nurserymen 

 abroad as P. tomentosa. Forms of this species are 

 probably hybrids with P. tremula. Eu. 



3. tomentdsa, Carr. (P. dlba var. tomentosa, Wesm. 

 P. dlba var. denudata, Maxim. P. pekinensis, L. 

 Henry. P. glabrata, Dode). WHITE POPLAR of China. 

 Large tree, similar to P. alba: Ivs. thick, on long shoots 

 of mature trees large (46 in. long), triangular-ovate, 

 not lobed, the broad base truncate or subcordate, 

 acuminate, margin sparingly sinuate-toothed, shining 

 dark green above and glabrescent beneath; on short 

 shoots small, ovate or triangular, cuneate, sinuate- 

 toothed, glabrous beneath; on vigorous shoots white- 

 tomentose beneath. N. China, where it makes a large 

 tree, and is planted in temple gardens; the restless Ivs. 

 suggest the sound of falling rain. R.H. 1903, p. 355. 

 Hardy in Mass., but is said not to prop, from cuttings. 



II. ASPENS. Lvs. not lobed, broader-based than ovate- 

 form; mature Ivs. green or at least not white- 

 tomentose, glabrous or nearly so beneath, those on 

 strong-growing and short shoots not prominently 

 different; petiole usually distinctly flattened: 

 terminal buds not large or glutinous: trees of small 

 or intermediate stature, usually with trembling 

 foliage. 



4. tremula, Linn. EUROPEAN ASPEN. Fig. 3127. 

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

 but mostly small and of relatively slow growth, pro- 

 ducing suckers: Ivs. small and thin, round-oval, more or 

 less whitened beneath when young, bordered with deep 

 and rounded incurved teeth; If .-stalks long, slender and 

 flattened, giving a restless motion to the foliage: lf.- 

 buds small : catkins small, with hairy scales and stigma 

 deeply divided; stamens usually 6-8. Widely distribu- 

 ted in Eu. and Asia, in this country known chiefly 

 in its grafted weeping form (var. pendula, Hort.). 

 The eastern Asiatic and Chinese form is made var. 

 Davidiana by Schneider: always a slender tree, rarely 

 exceeding about 60 ft.: young Ivs. reddish purple and 

 handsome as they unfold: suckers freely: there is a 

 pubescent form of this variety. The drooping form of 

 the European aspen is perhaps the best weeping tree 

 amongst the poplars. The spray is light, any, and foun- 

 tain-like, quite unlike the more common weeping 

 forms of the native P. grandidentata, which present a 

 stiff angular 



form, a com- 

 bination that is 

 rarely pleasing. 

 A characteristic 

 feature of this 

 tree is the pro- 

 fusion of its very 

 long catkins that 

 appear in earli- 

 est spring, even 

 before our native 

 poplars are in 

 bloom. The 

 staminate or 

 male catkins are 

 particularly 

 pleasing, and 

 planters should choose that sex, if possible. Var. 

 pyramidalis, Hort., is a slender pyramidal form. 

 Var. Freynii, Herv. Lvs. rhombic in outline, cuneate 

 at base, ciliate, pubescent beneath when young. 

 France, Germany. Var. villosa, Wesm. Hairy on 

 young growths. Var. pseudograndidentata, Aschers. 

 & Graebn., see description under No. 5. P. adenopoda, 



3129. Populus tremuloides. (XK) 



