But its growth form is irregular and its branches are brittle and can litter the ground. I found a small tree in the park that is similar to this, but I'm not sure of the identification. A very hardy, fast growing tree with brittle wood which is subject to breakage. Siberian elm is a perennial deciduous tree that grows well in disturbed areas and blooms from March to May. Siberian elm was first introduced into this country in 1905 ( Wyman, 1951 ). It is associated with freshwater habitat. Identifying Ulmus pumila by leaves, bark, flowers, seeds and shape. The leaves are alternate, simple, elliptic to oblong-lanceolate, usually simple serrate and 2.54 to 8 cm long. It has a self-supporting growth form. Certainly, this IS what I have on my property. Leaves are smooth and dark green above, paler and nearly hairless beneath, and alternate from side to side along twigs.