Onion Burl?

[P. McKinley]

These pieces come from the trunk of a Red Maple that exhibited a sizable bulging growth. I thought it might contain something interesting inside so to the band saw it went. And this is what I found. A woodworker friend described this as an "onion burl".

The patter does show some of the same characteristics as a "normal" burl, but without a single eye. Its harder than the surrounding wood, is a dark reddish/brown, and has veins running throughout. I cut it up into large blocks and slathered latex paint on the end grain cuts. I'll let it dry for a year or so and then cut it into usable blocks for handles and such.

Can anyone shed light on this peculiar looking wood and the name "onion burl"?

 

[CarpScot]

Onion refers to the layers you can see in that picture, like rings in an onion when you cut into one. Onion burls are often more fragile than other burls as the rings are more likely to separate.

 

[P. McKinley]

Thank you CarpScot!

 

[Burl Source]

Out west we call that a bunion. Not a true burl.
Many people lump any mutated growth into the category of "Burl".
A lot of the time it can have some cool figure. Other times just swirly grain.
Pieces I have used were harder and heavier than the normal wood.
Once dry it held up as good as the normal wood. At least with maple.
Pine trees can form similar growths but they usually have sap layers and tend to fall apart.
Might be different where you are at.