If you click on the Plant Database tab above, you'll see a window in the upper right corner of the page that says "view our custom databases:" with a list of plant genera below it. Cannas are one of the listed genera. Click on "Cannas" and it will take you to a page called "The Cannas Database" One of the options near the top of that page is "Access the general Cannas entry". Clicking on that gets you to the page I linked to above.
Let me know if any of the above doesn't make sense, sometimes my instructions create more confusion than help.