1880 ULMUS 



cloth covered with a sticky substance, which prevents 

 the ascent of the wingless female. Spray. A borer, 

 Saperda tridentata, sometimes does considerable dam- 

 age to the wood. The Elms grow best in rich and rather 

 moist soil, and the American Elm especially requires 

 such a soil to attain its full beauty, but some species, 

 as U. racemosa and 17. alata, do well in drier situations. 

 Elm trees are not difficult to transplant, and rather 

 large trees may be moved successfully if the work is 

 done carefully. They bear pruning well, but generally 

 do not need much attention of this kind. 



Propagated by seeds ripening usii;illv in :\Iay nr .Tune 

 and sown at once. Most of thi- sri-.U will t,'i rminate 

 after a few days, but some remain ili.rniMiit until the 

 following spring. Increased also by layers, which are 

 usually put down in autumn and are fit to be removed in 

 one year. A moist and rather light soil is best for this 

 method. Trees raised from layers are said to bear seed 

 less early and less profusely and are therefore espe- 

 cially recommended for street trees, as the foliage of 

 trees that fruit slightly or not at all is larger and more 

 abundant. Dwarf forms of U. campe.stris and also U. 

 part'ifolin and pitinila may be raised from greenwood 

 cuttings under glass, the cuttings growing most readily 

 if taken from forced plants. P. campestris and some 

 of its vars. are also propagated by suckers. In nurseries 

 most of the vars. are propagated by grafting, either by 

 budding in summer or by whip- or splice-grafting in 

 spring outdoors or on potted stock in the greenhouse. 

 &. Americana, campestris and scabra are used for 



rii 



uted 



ULMUS 



looming in spring, before the Ivs.: 

 calyx notdirided belowthemiddle. 

 J''ls. on slender pedicels, droop- 

 ing: fr. ciliute. 

 3. Pr. glabrous except the eiliafe 

 margin; branches ivithoiit 



V. ll:7'.l; 20:10. M.D.O. I'.nim,:;mj :;:,l m„,. ,,r tl.r fa- 

 vorite avenue trees in the niirtlic;i^i. in ^t:ili.^. Til. i:ini 

 varies considerably in habit, :mmI iIm- LilhuviiiL' Imins 

 have'been distinguished. The " v;l~i- f..rnr': the main 

 trunk separates at 15 to 30 ft. into several almost e<mal 

 branches, which diverge at first slightly and gradually, 

 but at the height of 50-70 ft. sweep boldly outwards and 

 form a broad, flat head, with the branches drooping at 

 the extremities. This is the most beautiful and also 

 the commonest form. Fig. 2617. The "plume form " is 

 much like the foregoing, but the trunk is less divided 

 and the limbs form few feathery plumes or rarely one. 

 The "weeping-willow form" usually has a rather short 

 trunk with limbs curving outward more rapidly and 

 with long and very slender pendulous branches, forming 

 usually a broad and round head. The "oak-tree form " 



.s ,,, 



pear in any of the forms named, but is most conspicucnis 

 in trees of the plume form. Fig. 2618. There are a few 

 named varieties in nurseries: Var. aiaea.. Temple, with 

 yellow foliage, found Th Vermont by F. L. Temple; var. 

 nina, Hort., a dwarf, compact form, which may perhaps 

 not belong to this species, and var. pendula, Ait., with 

 slender pendulous branches. * 



2. pedunculata, Poug. (J7. lavis. Pall. U. effusa, 

 Willd. U. cilidta, Ehrh. tT. racemdsu, Borkh., not 

 Thomas). Tree, attaining 100 ft., with spreading 

 branches, forming a broad open head: branchlets pu- 

 bescent, usually until the second year: buds glabrous, 

 acute: Ivs. oval or obovate, very unequal at base, acu- 

 minate, sharply doubly serrate, usually glabrous above, 

 pubescent beneath, 2-4 in. long: fls. slender-pediceled; 

 calyx with 6-8 exsertefl stamens: fr. ovate, notched, the 



