Ulmus Laciniata Var. Nikkoensis

Ulmus Laciniata Var. Nikkoensis

The Manchurian or Laciniate Elm Ulmus laciniata variety nikkoensis, commonly known as the Nikko Elm, was discovered as a seedling near Lake Chuzenji, near Nikkō, Japan, and obtained by the Arnold Arboretum in 1905. 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.

Significantly, the variety was not recognized by Ohwi, though his reasons are not clear.