Mysterious woody stumps in yard

Question: Hi, we live in Wayzata and have lived in our house for about three years.  Part of our yard is wetland and part is fenced in yard with a number of large trees, particularly Cottonwoods.  We have noticed the emergence of a number of woody stumps emerging in the back yard.  Some are sort of black and crumbly when disturbed and some appear to be sort of red bulbous and rootlike when disturbed.  They seem to be increasing in number and growing.  They are becoming a hazard for tripping and lawn mowing.  Any advice for removal, mitigation or prevention would be greatly appreciated.  See attached photos.

responder: An Ask Extension Expert Replied July 19, 2024, 7:24 PM EDT
response: Thank you for your question.  It has been referred to me.  A few questions for you. 1).  Has there been any change in these structures from when you first brought them to our attention? 2).  Are they more or less just lying on top of the ground or do they appear to be firmly attached? 3).  Are the additional structures appearing close to the ones in your picture or are they some distance (10 feet or more) removed? 4).  Are they soft to the touch or very hard? At this point, I don't know what they are; just gathering information. Many thanks.

responder: The Question Asker Replied July 30, 2024, 3:27 PM EDT
response: Hello,  Thank you very much for your reply and sorry for my slow response.  Please see my responses in [[    ]] below.  Much appreciated,  Rob  Sent from my iPad On Jul 19, 2024, at 7:41 PM, Ask Extension <<personal data hidden>> wrote:   ﻿

responder: An Ask Extension Expert Replied July 30, 2024, 5:06 PM EDT
response: Unfortuntely nothing was received n our end.  Please try again.

responder: The Question Asker Replied July 31, 2024, 2:16 PM EDT
response: Resending with fewer pictures and lower resolution.  Thanks Sent from my iPad Begin forwarded message:  From: Robert Goedken <<personal data hidden>>Date: July 31, 2024 at 7:23:31 AM CDTTo: Rob Goedken <<personal data hidden>>Subject: Fwd: Mysterious woody stumps in yard (#0147353)  ﻿Sent from my iPad Begin forwarded message:  From: Robert Goedken <<personal data hidden>>Date: July 30, 2024 at 2:25:27 PM CDTTo: Ask Extension <<personal data hidden>>Subject: Re: Mysterious woody stumps in yard (#0147353)  ﻿Hello,  Thank you very much for your reply and sorry for my slow response.  Please see my responses in [[    ]] below.  Much appreciated,  Rob  Sent from my iPad On Jul 19, 2024, at 7:41 PM, Ask Extension <<personal data hidden>> wrote:   ﻿

responder: An Ask Extension Expert Replied August 01, 2024, 12:48 AM EDT
response: Good evening.  Once again nothing was received by us with respect to your remarks.

responder: An Ask Extension Expert Replied August 06, 2024, 11:49 PM EDT
response: I would like to close your question.  I have not received any further information from you.  Do you think that these deposits are bear droppings? Looking forward to hearing back from you.

responder: The Question Asker Replied August 07, 2024, 3:45 PM EDT
response: Hi,  Sorry for the delay in responding.  Unfortunately, my prior responses and photos apparently did not get through your tech interface.  I’ll try one last time with an all text response.  I have pasted your questions with my answers below:  Thank you for your question.  It has been referred to me.  A few questions for you. 1).  Has there been any change in these structures from when you first brought them to our attention? [[Yes, they appear to be growing.  A few of them now seem to be an inch or more above ground.]] 2).  Are they more or less just lying on top of the ground or do they appear to be firmly attached? [[They are definitely firmly attached. Some have a brown crumbly consistency around the edges, but I took a knife and cut into them and they seem to be whitish/yellow in color and very dense.  It's almost like cutting into a pineapple, but even more dense.  It is definitely some type of live plant or fungus.]] 3).  Are the additional structures appearing close to the ones in your picture or are they some distance (10 feet or more) removed? [[There are probably six or so.  Them seem separated by 8 to 15 feet apart.  Some near the roots of a mature maple, others seemingly out in the open but possibly originating from a long removed mature tree.]] 4).  Are they soft to the touch or very hard?  [[Pretty hard to the touch.  I had to really saw at them with a knife to penetrate them for the pictures.  See below.]] At this point, I don't know what they are; just gathering information.     In response to your last question, NO, they are absolutely not bear droppings.  There are no bears in Wayzata to my knowledge and this is a fenced in yard.  If you have trouble with this message, I would love to have a phone call to discuss.  My number is 952/270-8220.  Thanks,  Rob     On Aug 6, 2024, at 10:49 PM, Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied August 07, 2024, 8:56 PM EDT
response: Thanks for getting back to us. At this point I am leaning towards the idea that these structures are some type of fungi. Unfortunately fungi identification is typically outside of the expertise of Extension Master Gardeners. I would suggest that you contact the Minnesota Mycological Society: https://minnesotamycologicalsociety.org/ More specifically to obtain a possible identification, please contact the following individual of the Society through his email: Ron Spinosa: <personal data hidden> Good luck. I apologize for being unable to provide a more positive identification. Thanks for using our forum.