Tax on Stock Dividend

My mother died 1-22-2011. I inherited shares of a family owned company where only family owns the stock. I was paid a dividend on this stock, I inherited the stock in march 2011 and was put in my name then.

I received a dividend in june 2011. I have a very low income and do not pay any income tax, just self-employment tax. do i owe 10% federal tax on this dividend or 0%? my mother had the stock for over 40 years.