Tree looks like oak but wrong "flowers"

Tree looks like oak but wrong

Observation - Tree looks like oak but wrong "flowers". Description: Found on FC land in the Upper Swansea Valley. Looks like Oak leaves but the flowers are wrong. Tree same all over - no sign of seed.

Found on FC land in the Upper Swansea Valley. Looks like Oak leaves but the "flowers" are wrong. Tree same all over - no sign of seed.