Mushrooms & Compost

In lawns, such large mushrooms are likely from wood-decay fungi growing underground on dead or dying tree roots. Is there a tree nearby ("nearby" being within about fifty feet or so) or was a tree removed in the past five or so years? They are harmless to the lawn and probably perfectly safe to add to compost if picked. (Do not consume any, of course.) Removing the mushrooms is like picking flowers or fruit though...the plant (in this case the body of the fungus) remains, and continues to grow normally. This is not problematic, but rather an explanation of why you may continue to see them appear after removal.

Information can be found in various places depending on how in-depth you wish to go with exploring the area's wide array of fungi.

• This tome by the USDA's Forest Service is quite wide-ranging and is broken-down by ecosystem: https://www.fs.fed.us/nrs/pubs/gtr/gtr_nrs79.pdf
• There are also local blogs and social media groups such as Facebook's "Maryland Mushrooms and Mycology" public group and others which are more international that are fairly good and quick with mushroom ID if given good photographs.
  
• This is a very light introductory page from the MD government: https://msa.maryland.gov/msa/mdmanual/01glance/wildlife/fungi/html/fungi.html
  
• The Maryland Biodiversity Project collects images of all life in Maryland and has an extensive catalog, including of fungi (see their top drop-down menu): https://www.marylandbiodiversity.com/. Nearly 650 species have entries, though not all of them have photographs yet.
  

Yes there is a living oak tree near by as well as other trees seen in the below picture.

The mushroom are probably growing on one or more of these tree roots, then. If the tree(s) appears to be in good condition, then there is probably no need for concern.

Miri