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Many trees only flower at a particular time during the year but when present they can be helpful to help with tree identification.

Trees have different strategies when it comes to reproduction. Broadleaf trees have flowers that contain the reproductive organs, and most conifers have cones for reproduction. 

  • Hermaphroditic trees, such as cherries, produce flowers with both male and female parts.
  • Unisexual trees include birches and have male and female parts on separate flowers.
  • Photograph of male willow flowers on catkins
    Male catkins of willow
    Monoecious trees, such as alder, bear separate male and female flowers on the same tree.
  • Dioecious trees, for instance holly and yew, have separate male and female trees.

Flower arrangement

Flowers occur in a variety of shapes, sizes and arrangements.

  • Solitary flowers - single flowers although they can appear to be in clusters.
  • Clusters - many small flowers form together in large branched groups as in elder.
  • Catkins - dense hanging spikes of tiny inconspicuous flowers such as those of willow.


Photograph of female hazel flowers
Tiny red styles of female hazel flower

Some flowers are so tiny you really need to get up close to see them. The stigmas of the female flowers of hazel are tiny, shocking pink tufts appearing from swollen buds in January.

Male and female flowers can also look very different, male alder catkins are long and yellow whereas female catkins are small green and egg shaped.


Flower colour can vary but for some species can be a defining feature. Apple and blackthorn blossom is usually white, where many catkins are yellow-green. Ash flowers are an unmistakable deep purple-red.

Top tip: flower arrangement is a key feature to use when identifying a tree.