How do I identify strange white patches and spiraled growths on my lawn?

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

1. 1
   Searching online images
2. 2
   Looking through previous forum questions
3. 3
   Spraying with metalaksil
4. 4
   Hosing off the affected area with a garden hose
5. 5
   Manually wiping off the substance
6. 6
   Waiting for the weeds to die off naturally from mowing
7. 7
   Hand-pulling the sprouts root and all
8. 8
   Manually digging out the clumped grass
9. 9
   Killing the affected area with herbicide and planting new seed
10. 10
    Searching for potential causes like pests, fungus, low spots, or buried obstructions
11. 11
    Probing the ground with a screwdriver to test for buried objects or rocks
12. 12
    Checking for window reflections or historical landscaping layouts
13. 13
    Waiting to see if it can be treated safely later
14. 14
    Applying specialized sedge killers like Sedgehammer or Empero once safety is determined

In their words

Unedited, most upvoted first, each linked to the thread it came from.