1880 



ULMUS 



the ground with cloth covered with a sticky substance, 

 which prevents the ascent of the wingless female. Spray. 

 A borer, Saperda tridentata, sometimes does consider- 

 able damage 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 U. 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 usually in May or June 

 and sown at once. Most of the seeds will germinate 

 after a few days, but some remain dormant 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. campestris and also U. 

 parvifolia and pumila may be raised from greenwood 

 cuttings under glass, the cuttings growing most readily 

 if taken from forced plants. U. 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. 

 U. Americana, campestris and scabra are used for 

 stocks. 



About 18 species of Ulmus are known, distributed 

 through the colder and temperate regions of the north- 

 ern hemisphere, in North America south to southern Mex- 

 ico, but none west of the Rocky Mts., and in Asia south 

 to the Himalayas. Trees with watery juice: Ivs. short- 

 petioled, usually unequal at the base, with caducous 

 stipules: fls. perfect or rarely polygamous, apetalous, in 

 axillary clusters or racemes; calyx campanulate, 4-9- 

 lobed, with an equal number of stamens (Fig. 2610): 

 ovary superior, with a 2-lobed style, usually 1-loculed 

 and with 1 ovule: fr. a slightly compressed dry nutlet, 

 with a broad, rarely narrow membranous wing all 

 around. Pigs. 2011-16. The wood is heavy, hard and 

 tough and often difficult to split. It is especially useful 

 in the jnanufacture of wagon-wheels, agricultural im- 

 plements and for boat-building. The inner mucilaginous 

 bark of the branches of U. fulva is used medicinally 

 and that of some Chinese species is made into meal and 

 used for food. The tough inner bark of some species 

 furnishes a kind of bass which is sometimes woven into 

 a coarse cloth, especially that of (j . campestris, var. 

 laciniata, in Japan. 



A. Blooming in spring, before the Ivs.: 

 calyx not divided below the middle. 

 B. Fls. on slender pedicels, droop- 

 ing: fr. ciliate. 



c. fr. glabrous except the ciliate 

 margin: branches without 

 corky wings 



cc. Fr. pubescent : branches often 

 with corky wings 



BB. Fls. short -pediceled in dense 



clusters, not pendulous, 

 .c. Buds covered with rusty hairs, 

 obtuse: fr. pubescent in the 



middle 



CC. Buds glabrous or pale pubes- 

 cent: fr. quite glabrous. 

 D. Lvs. doubly serrate, very un- 

 equal at base 



Americana 

 pedunculata 



racemosa 

 alata 



5. fulva 



scabra 

 campestris 



DD. Lvs. simply serrate, small, 



almost equal at the base... 8. pumila 

 AA. Blooming in the axils of this year's 

 Ivs. in summer or fall: calyx di- 

 vided below the middle. 

 B. Lvs. simply serrate, small: fr. 



gla brous 



BB. Lvs. doubly serrate: fr. pubescent. 



parvifolia 

 crassifolia 

 serotina 



1. Americana, Linn. (U. dlba, Rafin.). WHITE ELM. 

 WATER ELM. AMERICAN ELM. Figs. 2610, 2611, 2617, 

 2618. Tall, wide-spreading tree, attaining 120 ft., usually 

 with high, light gray trunk, limbs gradually outward- 

 curving with pendulous branches : branchlets pubescent 

 when young, glabrous in fall: buds acute, glabrous: 

 Ivs. obovate-oblong, very unequal at the base, acumi- 

 nate, doubly serrate, pubescent when young, at length 

 glabrous and rough above, pubescent or almost glabrous 

 be.neath, 3-6 in. long: fls. in many-fld. clusters; stamens 

 7-8, exserted : fr. oval or elliptic, veined, deeply notched, 

 incision reaching to the nutlet. Newfoundland to Fla., 

 west to the base of the Rocky Mts. S.S. 7:311. Em. 

 2:322. G.F. 3:443, 467; 6:175. Mn. 7, p. 125; 8, p. 71. 

 V. 14:79; 20:10. M.D.G. 1900:392-394. -One of the fa- 

 vorite avenue trees in the northeastern states. The Elm 

 varies considerably in habit, and the following forms 

 have been distinguished. The ''vase form ": the main 

 trunk separates at 15 to 30 ft. into several almost equal 

 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 " 

 is distinguished by its limbs spreading abruptly and in 

 sharp turns and the branches being usually less pendu- 

 lous. The name "Feathery" or "Fringed" Elm is ap- 

 plied to trees which have the limbs and the main trunk 

 clothed with short, somewhat pendent branchlets thrown 

 out usually in clusters at short intervals. This may ap- 

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

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

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

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

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

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

 slender pendulous branches. 



2. pedunculata, Foug. ( U. Icevis, Pall. U. efftixa, 

 Willd. U. ciliata, Ehrh. U. racemosa, 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 exserted stamens: fr. ovate, notched, the 



