Reply from Chris Chadwell - it is
Rosa brunonis"Dear Maggi
Hardly a 'rock garden plant' but yes I can quickly and easily (often not the case) to provide a name and am happy to do so.
Labels often get lost or never existed. Or a name within the limits of what is known about the flora of the Himalaya - which has overall been poorly studied since the 1930s, particularly in the Indian districts, where field-work has been virtually non-existent or undertaken to a woeful standard (I am actually being quite generous in my description).
It is
ROSA BRUNONII - the 'Himalayan Musk Rose'; quite variable; not sure if anyone
has proposed names for any of the variants/variations. An old synonym was
ROSA MOSCHATA.
Have made quite a number of collections of this and usually it came with a species name.
I seem to recollect a 'Betty Sherriff's Rose' being described in 'The Plantsman' many years ago.
Also see this species in flower in my garden (FLOWERINGS IN JUNE) see:
http://www.chadwellseeds.co.uk/slough-england (near the foot of the page)
The form I have in the rear section of my humble garden flowered well this year, with particularly large blooms.
Best Wishes,
Chris Chadwell
81 Parlaunt Road
SLOUGH
SL3 8BE
UK
www.chadwellseeds.co.uk Many thanks to Chris for his help!