The obituary in 'Irish Gardening' of January 1918 seems to confirm beyond a doubt that Andrew Campbell, the Head Gardener at St. Anne's, Clontarf, was the raiser of 'Souvenir de St. Anne's'. The tribute written by Lady Ardilaun ends with her relating his final wishes, and, considering this, it would be wonderful if his name could be added here as the raiser to finally acknowledge and recognise his connection to the rose.
"He suffered terrible tortures during his long illness to my great sorrow, but he bore it all with unfailing courage and patience. I saw him the day before he died, and he said his great desire was that I would continue to love the garden, and to take care of all the plants that he had raised, and to remember him in connection with them."
Although it isn't impossible that it's a seedling from a rare hip of 'Souvenir de la Malmaison' which Campbell planted, in most likelihood it's a sport. I've grown neither but there are enough opinions from others that they are the same except for the petal count. It's triploid too; a seedling might have more likely reverted to a diploid or even possibly jumped up to a tetraploid.
I spent some time with Souvenir de St Anne’s this week, giving it a trim and taking out the dead wood. It’s a well established bush that takes care of itself apart from summer watering and the occasional handful of fertiliser. We have hot, dry summers; mild, frost-free winters. Noticed a small hip and cannot recall seeing a hip on this rose in the past. It is about 1cm in diameter and just beginning to show some colour. Has anyone who grows Souvenir de St Anne’s found that their plants set hips?