Sticta carolinensis
Sticta carolinensis
- has the smallest thallus lobes of the regional Sticta species, evident from 10 feet away
- has a white lower surface (at least at the margins), also usually evident from 10 feet away in scatteringly upturned lobe tips;
- usually has so many phyllidia as to obscure the upper surface of the lobes beneath a cloud of phyllidia (also evident from quite a distance)
Examples:
https://www.inaturalist.org/observations/191172180
https://www.inaturalist.org/observations/196544433
https://www.inaturalist.org/observations/105498559
https://www.inaturalist.org/observations/102299320
https://www.inaturalist.org/observations/109238907
https://www.inaturalist.org/observations/108670187
https://www.inaturalist.org/observations/101351242
The other regional (North Carolina and thereabouts):
Sticta beauvoisii : much larger thallus sections (width and length) than Sticta carolinensis; lower surface deep brown with white cyphellae (craters that show the white medulla); phyllidia (sometimes copious) at the margins of the thallus lobes, usually not across the upper surface
https://www.inaturalist.org/observations/127903689
https://www.inaturalist.org/observations/148786942
https://www.inaturalist.org/observations/101780376Sticta fragilinata : same size as Sticta beauvoisii (so larger dimensions than Sticta carolinensis); lower surface brown with orange cyhpellae (craters that show the orange medulla); thallus lobes are themselves lobulate, often so abundantly as to be frilled
https://www.inaturalist.org/observations/151498715
https://www.inaturalist.org/observations/152951212
https://www.inaturalist.org/observations/152175429Sticta fuliginosa : very uncommon; single lobe ; isidia across the surface ; white cyphellae on lower surface
https://www.inaturalist.org/observations/152951530
- - - - - -
Lobarina scrobiculata : rare ; Sticta-like yet not Sticta (so much so that it can be confused with Sticta limbata) ; thallus size similar to Sticta beauvoisii ; hydrated thallus gray-green, not brown.
https://www.inaturalist.org/observations/152764826
https://www.inaturalist.org/observations/143209615