Little yellow flowers on 3 plants on Burnaby Mountain trails

Hello,

Can anyone identify the following 3 plants? They were all found on Burnaby Mountain trails recently. They all have little yellow plants but have very different leaf shapes. Am I correct in guessing that A and A2 are the same plant, and that the balls seen in A2 are the fertilized fruits or seeds that form in the place of the former flowers? Thanks. Jason

 

1 and 2 show Geum urbanum.

 

Thanks!

 

3. Mycelis muralis

4. Lapsana communis

 

Thank you!