As well as P Fruiticosa I have two other shrubby potentillas (about 20 years old so labels long gone).
Leaves and flowers are the same as P Fruiticosa but the stems are more upright and woody.
Any idea what type they are?
Different cultivars of P. fruticosa? There are many.
In the sticks near Peterborough
edited September 2018
What colour are the flowers?
This link may help it has a list by flower colour a couple get mentioned as being upright.
Maybe you can study that.
eg page 6 mentions Mount Everest as upright...white flowers.
Perthshire. SCOTLAND .
Surfer. Thanks for the link.
'Mount Everest' is a contender but I think they are probably 'Wychbold White' (last on the list) bred by Webbs of Wychbold as I bought a lot of plants from them when my daughter lived in that area.