Eucalyptus corrugata of the family Myrtaceae. Native to Western Australia and also known as rib-fruited mallee, this tree grows to 10 to 30 feet high and not particularly thick. I have never seen even pictures of the lumber, just the burl, which I believe is a root burl. I have never had a piece myself.
my samples: NOTE: these pics were all taken in very bright incandescent lighting ("soft white" at 2700K) colors will vary under other lighting conditions
burl and closeup
burl pen blanks
top and bottom of a really beautifully executed burl bowl
burl bowl listed as corrugata, but to me this looks a LOT more like York gum burl
Although this bowl was listed just as corrugata, I have seen similar pieces labeled "gummy" corrugata