SUNSET WITH PURPLE?

My title has a question mark at the end because no one on our northeasternWisconsin lake knows what plant this is on my neighbor's property.  Joe and his family live to the west of my lake cottage and he was excited when my friend, Lori, and I came to paint on his property.  His cabin would have been a nice subject but flowers usually catch my interest and these purple flowers? with their height and color grabbed my attention. Setting up to paint them was a challenge though since Joe's property has quite a sloping yard down to the lake.  Thank goodness for adjustable legs on my easel!  If only my own legs adjusted as well, I would have been more comfortable as I painted.  After visiting with Joe for a time and sketching in my subject - the purple flowers? - it was time to settle in to paint quickly as the sun started to go down.  Later that evening I googled purple perennial flowers and couldn't find a match.  Then I looked in my gardening books (I have a lot of gardening books) and didn't find a match.  Do you happen to know what they are called?  They are about 4 feet tall and grow on the southern bank above the lake in full sun.  If you might know their name please let me know in the comment section below this post.  Once I have their name I can order some for my own garden. Thank you. 

Sunset Memory

Painting in plein air is so exciting!  You don't know if a storm will catch you in the middle of a field, a bull might charge you from afar, or a nest of irate fire ants will decide to attack while you are setting up your gear.  The most memorable outdoor painting adventure has none of the above, but instead includes a fellow painter to share the outdoor painting experience.  This painting 'Sunset Memory' included oil painter, Lori.  (www.loriberinger.com)  We painted together for one wonderful week in beautiful Central Florida on the banks of the St. John's River.