A Springfield bank will process Illinois sales taxes from cash medical marijuana purchases after submitting the only bid for the contract.  Illinois National Bank executives said Thursday they decided to submit a bid after assurances from state and federal banking regulators regarding handling cash from Illinois’ pilot medical marijuana program.  The state had been having trouble finding a bank or company to process the cash.  The marijuana industry tends to operate with cash only, and banks are wary because marijuana is considered an illegal drug by the federal government.  The U.S. Treasury Department has issued guidance meant to clarify financial institutions can provide services to businesses selling marijuana.  Illinois National Bank executive vice president Patrick Phalen tells the Springfield State Journal-Register that the bank is simply collecting another form of state revenue.