The leaves are described as 'deeply divided' ... I can't find a photo but I'm pretty sure I've seen it at The Old Vicarage at East Ruston. I've certainly seen it somewhere ...
I do agree that the leaves look quite similar but they are an acid yellow now and really glow in the garden. Here’s another look.
Posts
https://www.whiteflowerfarm.com/aconitum-x-cammarum-bicolor
I know it should be flowering now, but a lot of flowers are doing odd things following the heat this year.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
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Below is Valerian officinalis..common Valerian..flowers here in June.
You say leaves are yellow and smaller.
Are they yellow in summer?
(My Valerian officianalis pics were taken in June.)