One author, speculating about the coming of a new ice age, pointed to «evidence of (at least) five rapid hemispheric coolings of about 5 °C... each event spread over not more than about a century,» Flohn (1974), quote p. 385; one line of evidence was carbon - 14 studies of tree stumps in glacial deposits: Denton and Karlén (1973). (history.aip.org)
They can be found on tree stumps of regular and cedar trees, and are uncommon. (nookipedia.com)
«For alumilaria root, he was advised to prune two centimeters higher; for hypoxolon wood rot, the solution was to remove tree stumps in their entirety from his farm land; and for yellowing leaves he was advised to do a soil test and discovered a nitrogen deficiency,» Barthorpe says. (fooddrink-magazine.com)