| Ulmus lanceifolia | |
|---|---|
 | |
| U. lanceifolia foliage, | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Rosales |
| Family: | Ulmaceae |
| Genus: | Ulmus |
| Subgenus: | U.subg. Ulmus |
| Section: | U.sect. Lanceifolia |
| Species: | U. lanceifolia |
| Binomial name | |
| Ulmus lanceifolia | |
| Synonyms[1] | |
| |
Ulmus lanceifolia, occasionally known as theVietnam elm, is a very large tree endemic to a wide area of southern Asia. Its range extends southeast and eastwards fromDarjeeling in theHimalaya, through Bangladesh, southern China, Myanmar (formerly Burma), Thailand, Laos, Vietnam and on discontinuously into Indonesia, straddling theEquator inSumatra andCelebes.
Ulmus lanceifolia can reach a maximum height of 45 m, placing it on a par with theEnglish Elm, but with pendulous branches; the bark of the trunk exfoliates in thin scales. The leaves, borne on wing-less branchlets, are narrow, generallylanceolate, < 10 × 3.5 cm, and thick.[2]Schneider's leaf-drawing (1907) shows some 16 vein-pairs.[3] The tree isdeciduous in the north of its range, where it can occur at altitudes of up to 2500 m, butevergreen in thetropics. Given the latitudinal range, there is inevitably a substantial variation in its flowering time, beginning in October in the north, but advancing to February–March in the south. The obovatesamarae are 12–30 mm long by 11–24 mm broad.[4][5]Ploidy:2n = 28.[6]
U. lanceifolia was found to be among the least suitable elms for feeding and reproduction by the adult elm leaf beetleXanthogaleruca luteola[7] and feeding by the Japanese BeetlePopillia japonica[8] in the United States.
Not cold-hardy, the species is very rare in cultivation; specimens introduced to the Netherlands from the Himalaya byHeybroek in the 1960s all perished.[9]
