Help Needed: Tree Identification

We have a group of 3 curious trees
in our back, moderately wooded pasture
which we cannot identify.
And what makes it curious, you ask ?
It is blooming NOW ... and it's AUTUMN.
*
This are of the pasture is mostly (80%) shade.
*
The soil is rich woodland soil, although
it is rather rocky (flat "stack stone" type rocks).
*
Our home is technically "on the line"
between regular and "higher elevation"
according to the local Forest Ranger.
So identifications of natural things
can be from either "area".
(We are in SE Tennessee.)
*
Above: Looking up into the tree's canopy.
(large leaves, nut clusters, and if you look very closely
you can see that there are a few purple
blooms still attached)
*
Below: Leaves (Cherub 1's hand for "size")
The leaves are very smooth
but not slick on the front.
On the back side, the leaves are
covered in a fine fuzz -
not soft, but not rough in texture.

Below: Closer photo for tree bark detail. The bark
feels rather smooth despite these markings. It also
appears to be very thin (not think like an Oak).

Below: Cherub 1 and Cherub 3 standing in and beside
two of the trees in this cluster. These trees are not very big,
yet they have fairly large canopies compared to their small
size. And when closely inspecting damage and "injuries"
on the trunks, we definitely came to the conclusion
that these are mature trees, albeit small.
*
(Note: We cannot find any more of these trees
in the other wooded areas, nor anywhere else
in this "patch" of woods. But according to neighbors,
this pasture has been "just" pasture
for 30 years or more.)

Below: This is a cluster of nuts found not far from the
base of these trees. The shells are all open, are very dry,
and very brittle. Also, their "hulls" are rather thin,
although they are stronger than we expected.

Above: half shells from a single seed pod.
*
Below: This tree is dropping light purple trumpet-shaped
blossoms. And at the base of each blossom is a soft
tan-brown "container" that rather looks like
a puff-ball mushroom (it feels almost like soft suede).
The tan container is very soft and supple -- not hard.

Above & Below: Close up images of some blossoms
that have already fallen to the ground.

We have scoured our tree books and the internet,
to no avail. We tried Witch Hazels
(blooms are yellow and are quite different
from these purple trumpet blossoms)
and were tried willows of all sorts.
*
We're stumped !!
*
And so we are hoping, now, that someone
"out there" might know what this tree is ?
Or can at least have some ideas that
might help us along in our search ?
**
UPDATE:
A friend from our
Nature Study Group,
Miss P.B.,
identified our tree.
It's a Princess Tree,
also known as
an Empress Tree.
It is not an native tree,
hence
our difficulty with
the identification.
THANK YOU FOR
YOUR HELP, P.B. !!