Hello! In today’s tutorial we will look at what catkins are, which trees have catkins and how to identify them. Are you ready? Let’s get started!
What are catkins?
Believe it or not, catkins are actually flowers! Yes. Catkins grow on shrubs and trees and are dangly clusters of lots of tiny flowers. They just don’t look like flowers at first glance because they are not colourful and pretty.
There are two reasons for this. First, the petals on catkins are either so tiny and drab that you don’t notice them, or they do not actually have petals at all.
Secondly, they do not need to be bright and beautiful, because they do not need to attract birds, animals or insects. The pollen on catkin-bearing tree is usually wind-borne.
Did you know, that most catkin bearing trees are coloniser or pioneer species. They are the first trees to grow in a new area – often before the habitat can support a large variety of insects or other animals. So, they depend on the wind to help fertilise their flowers. And wind does not much care for fancy blooms or pretty petals!
Which trees do catkins grow on?
We have quite a few species of catkin-bearing trees, some with catkins that are more noticeable than others. And some bearing catkins, which you might not know are actually catkins! So, here are our main catkin-bearing trees.
- Sweet chestnut
Amongst these trees, the catkins you are most likely to spot on your nature walks, are: alder, birch, hazel and willow.
Are catkins male or female?
This is a good question! As you know, flowers can be male or female. The male flowers carry the pollen, which is used to fertilise the female flowers, which then produces the seeds. Some plants have their male flowers and female flowers on separate plants – these are called dioecious. And some have both their male and female flowers on the same plant – these are called monoecious. This is the same for trees.
For example, alder, hazel and birch are monoecious, which means both their male and female flowers grow on the same tree. But their flowers do not look the same. In these trees, their male flowers form the pollen-bearing catkins. While their female flowers are rather inconspicuous may be difficult to spot (at least in birch and hazel).
However, willow is dioecious. It’s male and female flowers grow on separate trees. But, in the willows’ case, and usefully for us, they both look like our typical catkin – making them easy to spot.
How to identify catkins
As mentioned earlier, we have quite a few catkin-bearing trees. But, among these, there are only four you are likely to spot readily on your nature walks. These are alder, birch, hazel and willow. So, here will shall focus on describing these. But, remember, you can see what all of these trees look like over in our field guides.
- Alder – The alder is really easy to identify by looking for its woody female cones. Yes, alder is a deciduous tree with cones! It’s catkins when young, are green with a lovely deep red pattern across their surface. They then length, soften and turn yellow once mature.
- Birch – This tree is distinguished by having catkins its catkins in little clusters of three or four, growing at the tips of its twigs. When young, they are brown in colour, turning fluffy and yellow once they mature.
- Hazel – These are the most obvious of all our catkins and can be spotted growing everywhere in hedgerows, woodlands and parks in the springtime. They start as pairs of stubby, mossy green catkins with a criss-cross of mustard yellow scale trims, growing at intervals down the stem. Then, they mature into soft, dangly, yellow catkins once mature.
- Willow – From little white puff balls, to long, cotton wool caterpillars, each willow species has its own unique style of catkin. But, if you see something puffy or fuzzy and buzzing with early insects, it is most likely a type of willow.
How well do you know your catkins?
Well! There we go… we now know what catkins are, which trees have catkins and how to identify them. I hope you enjoyed this tutorial? But, before we say goodbye, why not test your nature knowledge and see how well you know them…