Hybrid Black Poplar?

Hybrid Black Poplar?

Observation - Hybrid Black Poplar?. Description: I posted the other border of these trees last week thinking they were Lombardy Poplars. Now this line have produced yellowy-green catkins - does this make them female trees and the others (with red catkins) male?

I posted the other border of these trees last week thinking they were Lombardy Poplars. Now this line have produced yellowy-green catkins - does this make them female trees and the others (with red catkins) male?