|Quercus x warburgii|
|Author||A. Camus 1939|
|Synonyms||robur x rugosa
= obtusata Henry, not Bonpl.
|Growth habit||tall semi-evergreen tree;|
|Leaves||6-12 cm long, 3-7 cm wide; leathery, obovate to oblanceolate; apex rounded; base tapered, sometimes weakly auricled; margin with shallow, small lobes; dull green, rough above; lighter green beneath; both sides glabrous; copper-coloured leaves in spring;|
|Fruits||2.5 cm long, single or paired; rather thin stalk; cup hemispherical enclosing 1/3 of nut;|
Bark, twigs and
|young shoots glabrous, greenish brown;|
|Hardiness zone, habitat||hardy zone 7;|
1939, date of taxon description by A. Camus, it was named Q.obtusata
; in 1933, Warburg admitted it is a hybrid;
-- it is not quite sure that parents are robur and rugosa.
-- At Cambridge, one of the 2 original trees (the other being at Kew) reaches 20 m high, for a trunk 2m in diameter.