Looks like it has been tossed into a stripping tank, but you see the traces of black paint and the remains of stenciling. Looks like it is ca. 1830:
(from How to Restore and Decorate Chairs, by Roberta Ray Blanchard)
Here is the top-slat:and what I think I see on it, the typical striping at the sides, grapes and a pear on either side of a cornucopia (not so sure about the cornucopia; it certainly doesn't look like a vase...or is it?):
So far I haven't seen anything resembling this pattern in my reference books.
More pears, this time from sketching on the plane:
More chairs; these are the classroom chairs at Ye Olde Schoolhouse inWisconsin, with a quilt block on the seat of each, so cute and beautifully done!