40
Umbilicate
(of foliose thalli): attached by a single, more or less central point (e.g.
Dermatocarpon
,
Rhizoplaca
,
Umbilicaria
).
Umbonate
(of apothecia): provided with a column of sterile hyphae which protrudes from the
hymenium
in the form of a small, central wart (e.g. in
Lecidea umbonata
).
Uniseriate
(of spores): in a single row within the
ascus
.
Unitunicate
(of ascus walls):
the wall is composed of one layer only (a primitive character). See
also:
bitunicate
.
Urceolate
(of apothecia): deeply concave, pitcher-like in form (e.g. in
Diploschistes diacapsis
).
When young, urceolate
apothecia
may be confused with
perithecia
(see also
perithecioid
).
UV
: the colour of thallus or (mostly) of the medulla, as it appears under a UV lamp (in
darkness). Protect your eyes with adequate spectacles, and be sure that the material on which
you place your sample is not in itself reactive to UV (in principle, avoid white paper).
Several UV-lamps permit the observation both under short- and long-wave radiation. Short-
wave is the best for lichens.
Veins
(of thallus): vein-like thickenings or flattened structures differing in colour from the
lower surface of some foliose lichens, esp. in
Peltigera
. They are mostly very evident, and
should not be confused with small foldings of the lower surface of foliose lichens.
Verrucose
(of thallus): wart-like.
Zeorine
(of apothecia): A lecanorine apothecium with a proper margin completely surrounded
by a layer of photobionts reaching the lower part of the hymenium. This term is never used
in our keys.
Zonate
(of thallus): with concentric areas of different colour (e.g. in some forms of
Pertusaria
amara
).
INDEX
Growth forms and general appearance.......................................................................................................3
Colours .......................................................................................................................................................8
Organs for sexual reproduction..................................................................................................................9
Structures for vegetative reproduction .....................................................................................................15
Other structures ........................................................................................................................................19
Photobionts...............................................................................................................................................24
Spores.......................................................................................................................................................25
Spot tests ..................................................................................................................................................26
Glossary ...................................................................................................................................................28
