Can you add a photo of each so we can see the whole plant? The closeups are useful, but so is seeing the overall growth habit. Where are you located? Province in Canada, UK, etc?

The first looks to me like it will be a tree from that limited view.

while we are waiting for that info ... next to a fence .. aka.. bird perch ... my presumption is that anything that pops up ... is a free seeding problem plant .... that birds facilitate in spreading everywhere .... so i start with the presumption that most things are not welcomed ...

ken

ps: the alternative.. is that the fence stopped air borne seed from going further ...

The birds $free tree and vine service is everlasting. Deal with it! :)

Really, a willow, with those mini leaves along the stem? I've never seen that on any of the 10 willow species I'm familiar with, though of course there are dozens or hundreds of willow species so I could be wrong.

Various willows (Salix species) will produce those leaflets along the stems. Salix nigra for one; also Salix eriocephala and S. lasiolepis. And one with perhaps the most pronounced display of these leaflets is eared willow, Salix aurita, so-called because of the ear-like appearance of the leaflets. They are actually stipules and are often an identifying feature of the genus.

Thanks for all your input! We had some bad weather over the weekend which bent the plants badly, so I decided to pull then out when I was tidying up the garden.