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Simple or irregularly branched rhizines
.
Tomentum:
a dense layer of hairs on the underside of the thallus. Not to be confused with rhizines,
that are much more robust.
Veins:
typical of the genus
Peltigera
, they are located on the underside of the thallus. They can be
flat or raised, dark- or light-coloured.
Pruina:
crystal deposits on the surface of the thallus (usually white in colour), giving it a frosty
appearance.
Ridges:
the upper surface in some lichens is strongly ridged (e.g. in
Lobaria pulmonaria
).
