The common hawthorn is a shrub or small tree 5-14 metres (15 to 45 feet) tall, with a dense crown.
The hermaphrodite flowers are produced in late spring (May to early June in its native area) in corymbs of 5-25 together; each flower is about 10mm (half an inch) diameter, and has five white petals, numerous red stamens, and a single style; they are moderately fragrant.