Baden-Württemberg - Lichens of Wales

lichen thallus are often deformed and the typical
form is only acquired after first isolating and
cultivating.
1 Cell content of the algae ± blue-green, rarely
brown-green or ± brown. No defined
chromatophore, no recognizable pyrenoid,
coloring diffuse (blue-green algae) 2
1* Cell content of the algae pure green,
yellow-green, orange-green, orange, brown-
orange, or yellow with defined chromatophore,
sometimes with pyrenoids (green algae) 7
2 Cells single or in 2-8 gelatin packets (colonies),
spherical to ellipsoidal, all more or less similar
formed, never branching threads (squash
preparation !) . 3
2* Cells in branching threads 4
3 Cells surrounded by a thin, slimy, colorless, not
or indefinitely layered gelatin envelop, usually in
colonies of 2-4. In very rare silicate lichens
(Phylliscum) Chroococcus
3* Cells with ± thick, clearly encased together, for
the most part inflated gelatin envelop. The
envelop often reddish or violet near upper surface
parts of the lichen thallus (“Gloeocapsa s.str) or
yellow-brown to brown colored (“Xanthocapsa”)
Gloeocapsa
4 Threads made up of several cell series,
branching. Cells mostly brown-green, in aspect
mostly ± elliptical to rectangular, 9-15 x 3-11
µm. In small shrubby to filamentous lichens on
seeping moist silicate rocks (Ephebe, or
Spilonema) Stigonema
4* Threads made up a of single cell series,
unbranched or false branching 5
5 Cells uniformly rounded, about 3-7 µm wide, in
unbranched threads (with occasionally
intercalated colorless cells: heterocysts), either
lying loose in a gelatin mass and then chain- or
pearl necklace form (gelatin lichens) or clustered
in gelatin spheres (e.g. in Sticta, Nephroma,
Pannaria, and Parmeliella) Nostoc
5* Cells usually not uniformly round, broader than 5
µm, not rosary-like, sometimes branched
(branching often not to be observed in the lichen)
6
6 Threads not tapered toward the tips, cells oval,
about 9-16 µm long, with isolated intercalated
cells (heterocysts). E.g. in Polychidium,
Thermutis, and Petractis Scytonema
6! Threads tapered toward the tips, heterocysts only
basal (characteristic difficult to see)
Calothrix and related genera
6* With other characteristics: algae not surely
accessible.
7 Cell content orange, green-orange, orange-
yellow, or red-brown, in the lichen thallus more
often even yellow-green (to green). Cells very
thick-walled, cylindrical to barrel shaped, rarely
globose, to branching threads, but in the lichen
thallus even occurring in single cells or short cell
series. Lichen thallus in the case of abrasion
often orange, gold-yellow, gold-brown, or
brown-yellow. In crustose lichens or species
with fine hairy thallus threads Trentepohlia
7* Cell content pure green to yellow-green.
Abraded thallus not colored orange, gold-brown
etc.: “pure green” algae of the order
Chlorococcales and Ulotrichales 8
8 Cells ± subcylindrical with rounded to slightly
regenerated ends, single or united into short in
short threads. Chloroplasts along the wall. In
coniocarpic lichens Stichococcus
8* The majority of the cells spherical, ellipsoidal to
egg-shaped, single or in clumps or in small
packets, not in threads . 9
9 Cells narrowly ellipsoidal to broadly fusiform,
often curved (with only one convex side), with
one chloroplast against the wall, without
pyrenoid (e.g. the leading species of green algae
of Peltigera, and Solorina, in addition Dibaeis,
and Omphalina) . Coccomyxa
9* Cells spherical to short ellipsoidal 10
10 Cells mostly in pairs, separated by a thin to
normally thick wall, 4-7 µm in size, attacked by
the lichen fungus in the form of haustoria . .
micareoid green algae
10* With other characteristics, if paired, then larger:
(other) coccoid (coccoid or chlorococcoid) green
algae (e.g. Trebouxia, predominantly spherical,
1-celled, with central, ± lobed chloroplast;
Myrmecia, spherical to ellipsoidal, peripheral
chloroplast; Gloeocystis: cells rounded to eggshaped,
surrounded by a thick gelatin envelop
and united into colonies (in Bryophagus).
3 Determining the Lichens:
Overview of the Key
1 The fruiting body is a 1-2.5 cm high stalked capfungus
with lamellae on the underside. The basic
thallus gray to deep green, squamulose of small
globules Omphalina
1 Fruiting body is not a cap-fungus or fruiting
body is lacking 2
2 Fruiting body is a nearly ephemeral, narrow
club-like, unbranched, cream colored to above
all slightly orange colored above, non lichenized,
± fleshy fungus, -2 cm. Thallus of closely
overlapping green, sometimes coalescing into a
knobby crust. Sp. 8-12 x 1,2-3.5 µm. On peat or
sandy soil Multiclavula vernalis
2* Fruiting body otherwise, not a cap fungus, or
fruiting body lacking . 3
3 Lichen consisting of a basic small foliose,
squamulose or crustose part covering the
substrate and a ± upright, peg-form, cup-form or
other formed, simple to branched part
I: Fruticose Lichens
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