Mario's Luminous Skill Guide.

Canes are one handed.

According to Fiel and the extractions Canes are indeed one handed, but Dual Staves its part of a 3rd id that isn't Two or One Handed.

Here's a trick for you.

Look at an image, right click on it, and view it in a new tab. You'll see the ItemID in your URL bar.

If the second number in the ID is 3, it's one-handed.
4 = two-handed
2 = ??? (This is what Luminous Shining Rod is)