While researching a cardboard uniface ten cent note we have which is redeemable at Tousley's Saloon - with a horse depicted with the words on its side, STUMPTAIL CURRENCY, we found the below link which has many different early references that would be useful to the readers of The E-Sylum.

Stumptail Currency.—In the Western States they have had wild-cat and red-dog currency. To these are now added what they denote as “stump-tail currency.’ This term is used to signify the notes of those banks whose circulation has been based on bonds of the Southern States. Soon after the breaking out of the present rebellion, these bonds proved utterly worthless, and the banks which held them of a consequence caved in. Their issue became stump-tailed, that is, reduced to nihil. —Historical Magazine.

Stump-tail Currency. Before the war of secession, a term applied, in the West, to bank-notes of doubtful value, or depreciated paper currency. Stunts.

It was very much as a senator from an eastern state has said when his state was passing through this experience. He remarked that the members of the legislature had to sort their money each morning after reading the paper and throw away what was worthless. Paper money was called by various names such as "stump-tail currency," rag money, and shin plaster.