In article , Kay Easton
writes
In article , Helen
writes
I don't know if this is any help but in my Dorling Kindersley book of
Trees, there is a picture of 'Crataemespilus Grandiflora'. It
possesses both type of leaves. Quote from the book:

"Leaves - Elliptic to obovate, to 7.5cm (3in) long and 5cm (2in)
across, glossy green above, turning bright orange in Autumn; on
vigorous shoots deeply lobed."

Hmm. Ovate medlar leaves and lobed hawthorn leaves. Wouldn't explain
what this bizarre tree is, but suggests that a bi-generic hybrid bearing
both types of parental leaves is possible.

Graft hybrids might well display both types of parental leaves, but
there's very few such taxa. (A Google search finds +Crataegomespulus -
not the same as xCrataemespilus - +Pyrocydonia, +Laburnocytisus, and an
intrageneric one in Syringa.) But, AFAIK, +Laburnocytisus doesn't,
although it does have 2/3 types of flowers.

But there's plenty of precedent for plants having different shapes of
leaves on a single plant. Given the context, I'd suspect an obscure
species of oak.
--
Stewart Robert Hinsley