Which tree is recognized for its upright growth form among English oaks?

The tree recognized for its upright growth form among English oaks is Quercus robur 'Fastigiata'. This cultivar is specifically noted for its columnar shape, making it an ideal choice for landscape situations where vertical space is preferred or where a narrow profile is beneficial.

The term "Fastigiata" denotes a growth habit that is tightly upright, contrasting with the broader, spreading shape of standard English oaks (Quercus robur). This upright form is advantageous in urban environments or smaller gardens where space is limited, as it allows for the benefits of an oak tree without consuming a large area horizontally.

In contrast, the other options do not share the same upright characteristic. Zelkova serrata is known for its vase-like shape and wide canopy, Styrax japonicum is more rounded and spreading, and Quercus rubra, while an impressive tree, typically grows in a more rounded or broadly pyramidal form rather than the strict upright architecture of Quercus robur 'Fastigiata'.