Hypericum calycinum 'Brigadoon' (St. John's Wort)

Ooh la la.  One of the most interesting St. John's Wort out there.  We have this short spreading plant in the garden near the entrance to the Sunken Garden in the full sun.  Screaming yellow foliage and it only stands 12-18" tall.  Make sure to check this plant out when you visit Yew Dell next.