Ulmus laciniata var. nikkoensis
| Ulmus laciniata var. nikkoensis | |
|---|---|
| |
| Nikko Elm at the Morton Arboretum | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Rosales |
| Family: | Ulmaceae |
| Genus: | Ulmus |
| Species: | |
| Variety: | U. l. var. nikkoensis
|
| Trinomial name | |
| Ulmus laciniata var. nikkoensis | |
Ulmus laciniata var. nikkoensis Rehder, the Nikko elm, was discovered as a seedling near Lake Chūzenji, near Nikkō, Japan, and obtained by the Arnold Arboretum in 1905.[1] The taxonomy of the tree remains a matter of contention, and has been considered possibly a hybrid of U. laciniata and U. davidiana var. japonica. However, in crossability experiments at the Arnold Arboretum in the 1970s, U. laciniata, a protogynous species, was found to be incompatible with U. davidiana var. japonica, which is protandrous.[2]
Significantly, the variety was not recognized by Ohwi,[3] though his reasons are not clear.
Description
Var. nikkoensis is a small tree; the specimen at the Morton Arboretum likened to a cherry tree.[4] The tree is chiefly distinguished by leaves which are red on emergence, and toothed but not lobed as in the species. The perfect apetalous wind-pollinated flowers appear in March in England.
Pests and diseases
Heybroek found the tree provided 'relatively resistant' (to DED) progeny in the Dutch elm breeding programme.[1]
Cultivation
There are no known cultivars of this taxon, nor is it known to be in commerce beyond the United States.
Etymology
Var. nikkoensis is named for the Nikkō National Park near the city of Nikkō, 125 km north of Tokyo.
Accessions
- North America
- Arnold Arboretum, US. Acc. no. 17908, collected wild in Japan.
- Dawes Arboretum US.[5]Newark, Ohio, US. 2 trees, no acc. details available.
- Morton Arboretum, US. Acc. no. 180–84, received 28 February 1978 as scions from Arnold Arboretum (their accession #17908-D); 9 m tall in 2006.[6]
- Europe
- Grange Farm Arboretum, Sutton St James, Spalding, Lincolnshire, UK. Acc. no. 515
References
- ^ a b Heybroek, Hans M. (1981). "The Japanese elm species and their value for the Dutch elm breeding program" (PDF). Proceedings of the Dutch Elm Disease symposium and workshop, October 5–9, Winnipeg, Manitoba: 78–90.
- ^ Hans, A. S. (1981). "Compatibility and Crossability Studies in Ulmus". Silvae Genetica. 30: 4–5.
- ^ J, Ohwi (1965). Flora of Japan. Smithsonian Institution.
- ^ J., Grimshaw; Bayton, R. "New Trees - Recent Introductions to Cultivation". Royal Botanic Gardens, Kew, London.
- ^ "Collectionsgarden_Plant Search". Archived from the original on October 25, 2007.
- ^ "Nikko Elm - Ulmus laciniata var. 'nikkoensis'".