At those intervals that the board of directors may authorize, and after provision for required reserves, the board of directors may declare a dividend to be paid at different rates on different types of shares, at different rates and maturity dates in the case of share certificates, and at different rates on different types of share draft accounts. Dividends may be declared, in whole or in part, from profits or undivided earnings. Dividends credited may be accrued on various types of shares, share certificates, and share draft accounts as authorized by the board of directors.