Viburnum plicatum, (syn. V. plicatum f. tomentosum) is what this spreading viburnum is supposed to be, but I am none too sure whether it is. I think it might be V. p. ‘Mariesii’. Viburnum plicatum produces branches in layers, creating a tiered effect, rather like Cornus controversa. But this one has only the one layer. It has in fact twice tried to embark on a second layer, by sending up two or three stout shoots from the middle, but I have cut off the attempt each year as I really want to preserve this rather splendid tablecloth effect. In fact I photographed it about this time last year, when it had yet to adopt this pronounced spreading habit; this is the second photograph, but I like it much better as it is now. It is also at the foot of a young Cercidiphyllum japonicum tree, and I want to make sure that it doesn’t grow up into the Cercidiphyllum’s lowest branches or obscure the trunk which is so distinctive.
It is extremely effective groundcover, as absolutely nothing grows underneath it at all, and it colours well in the autumn. It is supposed to fruit, red turning to black, but I have not noticed this yet.