Sticta fuliginosa s. str.

Spotting in the Field

Sticta fuliginosa s. str. has no straightforward diagnostic character, and is mostly confirmed by the absence of the diagnostic characters of other species. It has one distinctive character that stands out in the field, however: mature thalli are larger than the other species in the Sticta fuliginosa s. lat. group. Very rarely recorded as fertile and fertile thalli could be confused with the more typically fertile species Sticta ciliata.

Young Thalli

The young thalli are singularly indistinct, but are flat like Sticta ciliata but lack any marginal cilia. except on damaged edges.

Mature Thalli

The mature thalli become quite large (up to 5 – 7cm across), and the size alone can stand out from populations of the usually abundant Sticta ciliata. Otherwise the thalli are also rounded in out line, but less regularly than either Sticta ciliata or Sticta fuliginoides and the thallus margins are plain to lightly revolute.

Summary

The main features are:

• Young thalli not trumpet or vase shaped and without marginal cilia.

• Large sized mature thalli, with a rounded outline but less regular that the other species and without recurved margins.

• Confirmed microscopically by the lack of papillae on cyphella membrane cells (x400 & cross section, but the cyphella surfaces are visibly smooth at x40 in contrast to Sticta ciliata, where the surfaces are visibly minutely bumpy at x40)