Catkin ID please

Shot the catkins at random at Terra Nova, by the edge of a pond.
Feeling strange to have 2 varieties on the same branch. Are they
male and female ? Are they alder catkins ?

 

Alnus sp..common name Alder.
Catkins are the male flowers, they start short and tight, as season goes on the grow longer, open and release the pollen which fertilises the female parts..green cones when young .... to give the mature cones as seen in your picture.

alnus green cones - Google Search

 

Very thankful for your instant reply and full explanation.

 

You have both current (2020) male and female catkins [flowers] there, and also old 2019 seed 'cones'

 

Thanks Michael for your clear annotations.
The female 2020 are really tricky for layman like me !

 

Looks like Alnus rubra.

 

Thanks.
That's what I have been thinking of !