| Ulmus bergmanniana | |
|---|---|
| Bergmann's Elm, Kew, London. Photo: Ronnie Nijboer, Bonte Hoek kwekerijen | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Rosales |
| Family: | Ulmaceae |
| Genus: | Ulmus |
| Species: | U. bergmanniana |
| Binomial name | |
| Ulmus bergmanniana C.K.Schneid. |
|
Bergmann's Elm Ulmus bergmanniana C. K. Schneid. is a deciduous tree found across much of China in forests at elevations of between 1500 m and 3000 m.
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The tree is very closely related to the Wych Elm Ulmus glabra; it can reach a height of 26 m with a wide-spreading crown, and a trunk of about 0.9 m d.b.h.[1] The bark is longitudinally fissured, and varies in colour from greyish-white to dark grey. The pubescent leaves range from obovate to elliptic, < 16 cm long, and bluish-green in colour [2].[2] The perfect, wind-pollinated apetalous flowers are produced on second-year shoots in February, followed by generally orbicular samarae < 16 mm in diameter. Branchlets do not possess the corky wings characteristic of many other elm species.
Resistant to Dutch elm disease, in trials [3] in Oklahoma it was also found to be eschewed by the elm leaf beetle Xanthogaleruca luteola [4], but further north at the Morton Arboretum was moderately to highly preferred by the insect. The species is also susceptible to the Elm Leafminer.[3]
The tree was introduced to the West in 1900. In trials in the USA it was found to propagate well, and also proved to be very winter hardy. There are no known cultivars of this taxon, nor is it known to be in commerce beyond the USA.
Two varieties are recognized: var. bergmanniana L.K.Fu, and var. lasiophylla C.K.Schneid..
Unclear; possibly named for the American botanist Louis Susette Bergmann, (1868-?).