My line is from Hugh Alexander's son William.(1850-1925). Hugh has always been a challenge, There's no record of his birth, that I can find and his death cert names Jane Campbell and no father. My sister was in contact with and elderly lady in Ireland several years ago, and she said that Hugh's father was Irish. However we lost contact with her.
Hugh was jailed in Wigton for stealing 10 stone of meal and apart from the description i mentioned before, he was described as dirty and his clothes ragged. I could not find anything about his son William b1843
I checked the burial records in Ayr and found that he was buried in Tarbolton churchyard along with his wife Jane McWilliam and granddaughter Margaret. William my GG grandfather is buried in the next plot.
That's about all I know about Hugh and like yourself I found lots of trees online which are not correct. So the advice about doing your own research and verifying, where possible, is good advice.
If there is anything else I can help with our Alexander family feel free to contact me
Regards
Ross