change site title as seen in dashboard (not individual pages)

Hi all

I am doing work for a client and want to change the "site title" of the website that is visible on the "dashboard" page ("reading + ridinig" in the attached screenshot). This is not to be confused with the name up in the tab of the browser or the name of the individual pages. It seems that the site title that is visible on the dashboard is being used for various things throughout the site such as in the verification email address when someone subscribes. How can I change this?

Thanks in advance.