I received an inheritance(cash)from my ex-mother-in-law who lived in Texas.I reside in
California.Are there inheritance taxes I'll need to pay?

You need to call the Franchise Tax Board to verify, but I believe there is NO inheritance tax and no estate tax in California.

There is no federal inheritance tax, and neither TX nor CA impose inheritance taxes either:

From the CA web site California Tax Information Center - Special Circumstances (http://www.taxes.ca.gov/Income_Tax/specialind.shtml)

California does not have a gift tax or an inheritance tax.

And from Texas's web site: Inheritance Tax (http://www.window.state.tx.us/taxinfo/inherit/index.html)
Please note that no state inheritance return is required on estates with a date of death on or after January 1, 2005.