Siberian elm

Siberian elm
Siberian elms in the Gobi Desert of Mongolia
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Rosales
Family:	Ulmaceae
Genus:	Ulmus
Species:	U. pumila
Binomial name
Ulmus pumila L.
Synonyms
Ulmus campestris var. pumila Ledeb. Ulmus campestris L. var. pumila (L.) Maxim. Ulmus gobicus Anon. Ulmus humilis Amman ex Steud. Ulmus manshurica Nakai Ulmus microphylla Persoon Ulmus pumila var. genuina Skvort. Ulmus pumila var. microphylla Persoon Ulmus pumila var. transbaicalensis Pallas

Ulmus pumila, the Siberian elm, is a tree native to Central Asia, eastern Siberia, the Russian Far East, Mongolia, Tibet, northern China, India (northern Kashmir) and Korea. It is also known as the Asiatic elm and dwarf elm, but sometimes miscalled the 'Chinese Elm' (Ulmus parvifolia). It is the last tree species encountered in the semi-desert regions of central Asia. Described by Pallas in the 18th century from specimens from Transbaikal, Ulmus pumila has been widely cultivated throughout the Americas, Asia and, to a lesser extent, southern Europe. It is naturalized across much of the United States.

The Siberian elm is usually a small to medium-sized, often bushy, tree growing to 10–20 m (35–65 ft) tall, with a trunk up to 176 cm (69 ¹⁄₄ in) d.b.h. The leaves are deciduous in cold areas, but semi-evergreen in warmer climates, less than 7 cm (2 ³⁄₄ in) long and less than 3 cm (1 ¹⁄₄ in) broad, with an oblique base and a coarsely serrated margin, changing from dark green to yellow in autumn.

The perfect, apetalous wind-pollinated flowers bloom for one week in early spring, before the leaves emerge, in tight fascicles (bundles) on last year's branchlets. Each flower is about 3 mm (¹⁄₈ in) across and has a green calyx with 4–5 lobes, 4–8 stamens with brownish-red anthers, and a green pistil with a two-lobed style. Unlike most elms, the Siberian elm is able to self-pollinate successfully.

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Wikipedia