These two are grouped together because they are both in the Betulaceae family and there aren’t that many of them, in the park. I know of only seven Alders so far.
Avenue Road
There are two Grey alders near the Avenue Road path, one by the small playground and the other about half way up, next to a Cypress oak. The leaves of the Grey alder are more pointed than the usual rounded leaves of the Common alder. Alder trees are quite easily identified by the false cones which are often still on the tree from the previous year. These are the fruit of the female catkin and produce many wind-borne seeds. The long purple dangling male catkins can be seen alongside new green female catkins in early Spring before the leaves come out.
Drive
There is a large Alder in the space between the drive and the path, behind one of the benches. It is a Common alder or Black alder or simply and Alder, Alnus glutinosa. It has the usual rounded leaves of the Common alder.
Pond
The Alder in the pond area is on the bank nearer to Avenue Road and is at the end nearer to the Grange Road car park. It’s near one of the benches on the edge of the pond. My App has identified it both as an Italian alder, Alnus cordata, and a Black alder, Alnus glutinosa. I’m going with the Italian alder, at the moment. The leaves are not the round shape of Black alder, they do not seem to have the same toothed edge as the Grey alder but they do not exactly look heart shaped which is what cordate means. Perhaps I just need to get some better photos.
Bottom of the park
The remaining Alder are towards the bottom of the park, just off the path that goes down the hill past the Thrive garden. Turn left off the path past the flower bed, over the little stream, and the Alders are in a line. The two nearest the path are Common or Black Alder and the third one is a Grey alder.
In September the pollinated female catkin has swollen and over the rest of Autumn will turn woody and brown. They can be seen alongside new, green male catkins, ready for next season, and old female catkins that have released their seed. The female catkins will be ready to release their seed early in Spring.
New female catkins can be seen in March when the male catkins mature and develop their characteristic purple scales and yellow flowers. The female catkin is quite small at this stage and it, too, looks purple.
Kings Heath Park Trees 