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Lecideine
(of apothecia): having a
margin
exclusively consisting of dark-coloured fungal
hyphae. This term is subsumed in our keys under
non-lecanorine.
See also
biatorine
,
lecanorine
,
zeorine
.
Leprose
(of thallus): a powdery mass of hydrophobic,
soredia
-like granules. Some experience is
needed to distinguish truly leprose thalli from crustose thalli with abundant, diffuse
soredia
.
Lichenised
(of mycobionts):
always growing in symbiosis with a
photobiont
. In certain groups,
e.g.
Arthonia
, some species are clearly lichenised, others are clearly non-lichenised, (no true
lichens), still others are of uncertain attribution.
Linear
(of pseudocyphellae): when well-developed, narrow and elongated.
Lirelliform
(of apothecia): a
non-lecanorine apothecium
with a long, narrow, elongate form
(e.g. of
Graphis
,
Opegrapha
).
Lobes
(of thalli): this term is used both for
foliose
and
crustose
lichens; it refers to flattened,
elongate structures developed at the margin of the
thalli
(e.g. in
Squamarina lentigera
), or
around the
apothecia
(e.g. in
Physconia venusta
). Their width should be measured in the
central part. See also
placodiomorph
.
Lobulate
: with small
lobes
.
Lugol
(of reactions): see
J.
Macroconidia
(singular: macroconidium): the larger
conidium
of a species that has more than
one type of conidium (e.g. in some species of
Micarea
, or
Porina
).
Maculiform
(of soralia):
laminal
soredia
grouped into more or less round patches. See also
punctiform
.
Maezedium
(plural: maezedia)
:
a mass of
spores
liberated continuously by the
asci
of
Caliciales
.
It appears as a powdery mass covering the
apothecium
.
Margin
(of apothecia):
apothecia
have two main types of margin: a) a
proper
margin consisting
of fungal
hyphae
only; usually, the colour of the proper margin is similar to that of the disc
and different from that of the thallus. b) a
thalline
margin, which includes
photobionts
;
usually of a colour similar to that of the thallus, and different from that of the disc (with
several exceptions. e.g. in
Caloplaca
). In our keys, unless otherwise specified, the term
“margin” always refers to the thalline margin for
lecanorine
apothecia, to the proper margin
for
non-lecanorine
apothecia.
Marginal
(of soralia):
soredia
limited to the marginal parts of thallus parts (usually
lobes
of
foliose
lichens).
Medulla
: in section, this is the “central” part of the
thallus
, located under the
photobiont
layer.
It is composed exclusively by loosely arranged fungal
hyphae
, the spaces between them
facilitating gas exchange for the photosynthetic partner. It can be compact, loose or almost
hollow, it can be
pigmented
or not, and it often contains lichens substances which are absent
in the
cortex
(hence, it can have peculiar reactions, or a characteristic colour under a UV-
lamp).
Micareoid
(of photobionts): green algae with a diameter of 4-7 mm, thin-walled, often
occurring in pairs (e.g. those of
Micarea
).
Microconidia
(singular: microconidium): the smaller
conidium
of a species that has more than
one type of conidium (e.g. in some species of
Micarea
).
Moniliform
(of hyphae): arranged in a thread consisting in a series of globose cells, looking like
a rosary, or the chains of
Nostoc
.
Mycelium
: the tissue composed by the fungal part of the lichen, consisting of
hyphae
.
Mycobiont
: the fungal symbiotic partner in a lichen.
Muriform
(of spores): looking like a brick-wall, many-celled, with many longitudinal
septa
and
crosswalls. See also
submuriform
.
Non-lecanorine
(of apothecia): without a thalline
margin
. See also
biatorine
,
lecanorine
,
zeorine
.
