At the moment, the ground underneath the beeches is strewn with the discarded male flower heads. Their function, to release pollen, has been completed.
En masse, they have created drifts of soft beige fluff.
Up close, each head is made up of a small pea-sized pompom holding out the spent stamens.
Wind-pollinated flowers are often less showy in their detail, but these flowers can be interesting, too.
Their morphology (features) gives clues about the role of wind in transferring pollen to produce seed.
The female flowers have no petals, are small and green with light brown hairs.
Once the two protruding stigmas have successfully received the wind-blown pollen, the flower develops over five to six months into a spiny fruit, enclosing two roughly triangular beech nuts.
Beech nuts are often called beech mast.
About every five to eight years, rarely two years in a row, an abundant, ''mast year'' of beech nuts occurs.
This usually happens in years following a hot, sunny and dry summer.
The shiny brown nuts maturing in autumn are edible, although slightly bitter and the hard seed coat makes getting a meal of them a slow-food task.
An avenue of mature European beech grows just north of the Castle St footbridge in the lower Dunedin Botanic Garden.
Marianne Groothuis is the camellia and theme plant collection curator at Dunedin Botanic Garden.
