[1] More recent authors most widely regarded it as a cultivar, either not ascribed to any Zelkova species in particular,[1] or placed under Z. carpinifolia with no suggestion of hybrid origin.
The fact that Z. X verschaffeltii is really a clone would indicate that such a cross might be a rare event, and our experience would tend to substantiate this hypothesis.
However, Hans M. Heybroek, erstwhile head of the Dutch elm breeding programme at the de Dorschkamp Research Institute for Forestry and Landscape Planning at Wageningen, identified the tree as Zelkova × verschaffeltii.
[4] A large shrub or small, bushy-crowned tree < 15 m tall, with mottled grey and brown bark and graceful habit.
The fruit is rarely produced, a small two-lobed dry nut-like drupe 4–5 mm diameter.