With a few Lunularia. See my Lunularia observation for additional notes. https://www.inaturalist.org/observations/158509549
On side of sage scrub trail, in mixed cryptogamic mat along with mosses, Crassula connata, and Riccia trichocarpa. I often see Riccia spp. and Asterella palmeri around here but this is the first time I have seen Sphaerocarpos in a (relatively) non-anthropogenic habitat. This thallus was unaccompanied by visible conspecifics.
Pic 2 shows habitat. Note the way it avoids the mulch.
In bare patch of otherwise-weedy staff only area. Pic 2 shows habitat (note that the exact patch it was found in is not pictured).
In middle of artificial garden path. Specimen has been extracted for culturing.
Very small, about 2 mm long. Found under a rock in a garden bed in a suburban backyard.
Across the road (but not directly across) from this tree:
https://www.inaturalist.org/observations/147445061
At roadside. Oddly enough, many other seemingly suitable Sphaerocarpos habitats at the H did not have any visible specimens.