830 Yearbook^ of Agriculture 1949 



greenish, in clusters in early spring. Fruits flattened, */ 2 inch in diameter. Native of western 

 and southern Europe. In the United States planted in moist temperate regions of Pacific 

 and Eastern States. Tolerant of city smoke but produces undesirable root sprouts. Subject 

 to Dutch elm disease and attacked by elm leaf beetle. Zone 5. 



39. SIBERIAN ELM, Ulmus pumila L. (Asiatic elm, Pekin elm, dwarf elm, dwarf Asiatic 

 elm; erroneously called Chinese elm, which is U. parvifolia Jacq., No. 40). Small to 

 medium-sized tree with rounded crown and rough bark. Twigs hairy when young. Leaves 

 in 2 rows, narrowly elliptical, small, % to 2 inches long, short-pointed, the two sides almost 

 equal, toothed, thick, smooth and dark green above, becoming smooth beneath. Flowers 

 small, greenish, in clusters in early spring. Fruits flattened, l /z inch in diameter. Native 

 from Turkestan to eastern Siberia and northern China. Widely grown in central and 

 western United States for shade and shelterbelts. Hardy in dry regions and drought- 

 resistant, tolerates city smoke and poor soils, and grows rapidly. Subject to cotton root 

 rot and canker disease. Zone 4. 



40. CHINESE ELM, Ulmus parvifolia Jacq. Small tree with broad rounded crown and 

 spreading 1 branches, shedding leaves in fall or half-evergreen in warm climates. Bark 

 smooth or rough. Twigs hairy. Leaves in 2 rows, elliptical, small, % to 2 inches long, 

 short-pointed, the two sides slightly unequal, toothed, thick and leathery, smooth and 

 shiny dark green above, paler and becoming nearly smooth beneath, turning to red or 

 purple or remaining green into winter in warm climates. Flowers small, greenish, in 

 clusters in fall. Fruits elliptical, % inch long, flattened. Native of northern and central 

 China, Korea, and Japan. Planted especially in Gulf and Pacific States but hardy north- 

 ward in the East. Used also for shelterbelts. Zone 5. 



41. WHITE WILLOW, Salix alba L. Medium-sized tree with spreading branches and 

 whitish foliage. Leaves lance-shaped, 2 to 4 inches long, long-pointed, finely toothed, 

 whitish and silky beneath. Male and female flowers on different trees in early spring, 

 minute, many in clusters 2 inches long. Capsules with cottony seeds. Native from Europe 

 and northern Africa to central Asia. Grown for ornament in moist temperate regions of 

 the United States and adjacent Canada, where it has become naturalized. A commonly 

 planted variety or hybrid of this species with yellow branches (yellowstem white willow, 

 golden willow; var. vitellina (L.) Stokes) is one of the basket willows. Both the typical 

 form and this variety have been used in shelterbelts in the North. Zone 2. 



42. WEEPING WILLOW, Salix babylonica L. (Babylon weeping willow). Small to 

 medium-sized tree with long, slender, drooping branches. Bark gray, rough and fissured. 

 Leaves narrowly lance-shaped, 2 to 6 inches long, long-pointed, finely toothed, dark green 

 above and paler beneath, smooth. Male and female flowers on different trees in early 

 spring, minute, many in clusters ^4 to 1 1 /2 inches long. Capsules with cottony seeds. Native 

 of China. Long planted for its weeping foliage as a lawn and landscape tree in eastern 

 United States, where it has become naturalized. Grown also in Western States. Adapted 

 to moist soil and tolerant of city smoke. Zone (5) . 



43. LOMBARDY POPLAR, Populus ntgra L. (black poplar is the typical variety; Lombardy 

 poplar is a hybrid clone known as var. italica Muenchh. ) . Medium-sized to tall columnar 

 tree with narrow crown of upright branches. Bark gray, furrowed. Leafstalks 1 to 2 

 inches long, slender, flattened. Leaf blades wedge-shaped or triangular, 1 l /z to 3 inches 

 long, long-pointed, the edges with curved teeth, smooth or slightly hairy. The trees are 

 male only and do not produce seeds, the male flowers many in clusters 2 inches long. 

 Black poplar is native of Europe and western Asia. Lombardy poplar, distinguished by 

 its columnar crown, is widely cultivated almost throughout the United States and 

 spreads by root-sprouts. Grown especially in rows for shelterbelts, roadside trees, and 

 formal effects. Short-lived and subject to European canker disease. Zone 2. 



44. CAROLINA POPLAR, XPopulus eugenei Simon-Louis (P. deltoidesXnigra var. 

 italica,, XP. canadensis Moench var. eugenei (Simon-Louis) Schelle). Large tree with 

 rounded, spreading crown. Bark gray, furrowed. Leafstalks 1 to 2 inches long, flattened. 

 Leaf blades triangular, 3 to 4 inches long, long-pointed, the edges with curved teeth, 

 shiny green and smooth on both sides. The trees are male only and not producing seeds, 

 the male flowers many in clusters 3 inches long in early spring. A hybrid clone which 

 probably originated in Europe. Extensively planted across the United States and spreads 

 from cultivation by root-sprouts. Tolerant of city smoke and dust and quick growing, 

 but not recommended for city planting because the roots penetrate sewers. Zone 4. 



38. English elm. 39. Siberian elm. 40. Chinese elm. 41. White willow. 42. Weep- 

 ing willow. 43. Lombardy poplar. 44. Carolina poplar. 45. White poplar. 46. 

 European white birch. 47. White mulberry. 48. London planetree. 49. Chinese 

 parasoltree. 50. English oak. 



