https://www.rhs.org.uk/plants/213852/viburnum-opulus-var-americanum/details
Viburnum opulus var. americanum | highbush cranberry Shrubs/RHS
viburnum opulushighbush cranberryvaramericanumshrubs
https://www.gardenersworld.com/plants/viburnum-opulus/
Viburnum opulus (Guelder rose) | BBC Gardeners World Magazine
Plant profile of Viburnum opulus (guelder rose) on gardenersworld.com
bbc gardeners worldviburnum opulusguelder rosemagazine
https://www.rhs.org.uk/plants/18920/viburnum-opulus-variegatum-(v)/details
Viburnum opulus 'Variegatum' (v) | /RHS
viburnum opulusrhs
https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/guelder-rose/
Guelder Rose (Viburnum opulus) - Woodland Trust
Find out all about guelder rose. Discover where it grows in the UK, how it helps wildlife and how to identify it.
guelder roseviburnum opuluswoodlandtrust
https://www.rhs.org.uk/plants/233363/viburnum-opulus-var-americanum-wentworth/details
Viburnum opulus var. americanum 'Wentworth' | /RHS
viburnum opulusvaramericanumwentworthrhs