Devon Tor
H. 'Devon Tor'
Looks very much like a its parent H. montana. This cultivar grows much larger than the registered dimensions suggest.

Alternative: H. 'Green Sheen'
Plant Size
  Giant: 30" x 83"  
Leaf
  13" x 11"; green  
Flower
  Pale purple  
Parentage
  H. montana selection x unknown  
Devon TorDevon Tor