Baden-Württemberg - Lichens of Wales

mealy, intensely citron yellow to yellow-green,
rarely whitish. Sp. colored to colorless 7
7 Ap. stalk and underside and the margin of the
capitulum yellow-green pruinose (at first also the
mazaedium), upper side (of the mazaedium) light
brown. Sp. globose, light, 1 celled. Thallus
yellow to yellow-green
Chaenotheca furfuracea
7* Sp. blackish, upper side of the capitulum (green)
black, black or dark brown, not yellow-green
pruinose. Sp. not globose, colored. Sessile or on
the algae layer of a whitish or yellow-green to
yellow, finely sorediate thallus . 8
8 Sp. 12-16 x 4-6 µm, dark brown, 2 celled. Ap.
short stalked, capitulum -0.5(0.7) mm wide.
Thallus light yellow to greenish, parasitic on a
whitish to beige crust . Calicium corynellum
8* Sp. 5-8(10) µm long, 1 or 2 celled. Capitulum -
0.3 mm wide. . . 9
9 Ap. 0.6-2(2.5) mm high, long stalked, blackish,
upper side of the capitulum with (green) black to
dark brown mazaedium. Stalk black. Sp. light,
5-8 x 2-2.5(3) µm, narrowly ellipsoidal to
cylindric, 1 celled, 2 celled when mature, spirally
ribbed. On (green) yellow Psilolechia lucida
and leprose crusts
. Microcalicium arenarium
9* Ap. -0.5 mm high, capitulum black, without
mazaedium, stalk light to black. Sp. 6-10 x 3-4
µm, 1 celled. On whitish to beige crusts
Chaenothecopsis exerta
10 On twigs and branches of alder and poplar. Ap.
black, capitula usually globose to ± top shaped,
without mazaedium. Sp. 1-4 celled, brown
GS Stenocybe
10* Not on alder or popular branches 11
11 Sp. 1 celled . 12
11* Sp. septate . 13
12 Ap. even the upper side of the capitula (almost)
black, without mazaedium, undersides and
margins not pruinose. Sp. narrowly ellipsoidal to
ellipsoidal, up to 10 x 3.5 µm large, brown, to
light brown. Usually without thallus or on a
foreign thallus . GS Chaenothecopsis
12* Ap. upper side with brown or lighter mazaedium,
not uncommonly the underside and
margins whitish or yellowish pruinose. Sp.
globose, more rarely ellipsoidal to cylindric,
colorless to brown. Thallus definite, more rarely
± lacking GS Chaenotheca
13 Capitula with brown mazaedium, underside and
at the margin yellow (green) pruinose. Sp. light
brown, with 1-3 indefinite septa, when mature
almost cylindric . Chaenotheca laevigata
13* Capitula without brown mazaedium, either shiny
black without mazaedium, or with black, rarely
yellowish pruinose mazaedium, underside and at
the margin black or brown, whitish or yellowish
pruinose. 14
14 Capitula with bulging black (rarely slightly
pruinose) mazaedium, black or brown on the
underside and at the margin, whitish or yellowish
pruinose, usually top-shaped to cup-shaped in
outline. Sp. (dark) brown, 2 celled, at best 3.5
µm wide. Ascus usually relatively rapidly
disintegratin Calicium
14* Capitula without bulging mazaedium, shiny
blackish. Sp. brown, or light brown. Ascus
persistent 15
15 Sp. 4 celled, 20-32 x 7-10 µm. Capitula globose
to 4 angled in outline. On old pines
Stenocybe
15* Sp. 2 celled . 16
16 Sp. 10-13 x 4-6 µm, 2 celled. On poplar
. Phaeocalicium populneum
16* Sp. up to 10 x 3 µm. Generally not on poplar
Chaenothecopsis
Genus Key V: Lichens with Perithecia
(pyrenocarpic lichens)
1 Fruiting body yellow to greenish yellow 2
1* Fruiting body not yellow to greenish yellow . 3
2 Fruiting body shining yellow to greenish yellow.
Sp. very many per ascus, 1 celled, small
Thelocarpon
2* Fruiting body yellowish (rose) to rose brown.
Sp. to 8, many celled, needle-like, very long .
Belonia
3 Thallus definitely foliose, for the most part, the
underside free from the substrate, single unit
rounded and attached at one place navel-like, or
multiple and closely crowded, attacked at several
places. One thallus usually about 0.8-4 cm wide.
Sp. 1 celled, colorless . Dermatocarpon
3* Thallus crustose or squamulose, squamules -1 cm
in size 4
4 Thallus squamulose or indefinitely lobed at the
margin, on soil, mosses, or rock. Per. Black.
Paraph. In ripe per. indefinite or lacking . 5
4* Thallus entirely crustose, coherent to areolate (to
clod-like) or granular or indefinite 8
5 Sp. muriform-multicellular, colorless to brown,
usually 2. With or without hymenial algae 6
5* Sp. 1-celled to cross-septate multicellular,
colorless. Without hymenial algae . 7
6 Thallus in fresh condition pale greenish to
greenish -brown (in the herbarium yellow to
gray-brown), moist shining green, very small
squamulose, squamules 0.3-1 mm, usually close
together and ± erect. Fruiting bodies conical to
barrel shaped, with warty upper surface, sessile to
moderately sunken, often between the squamules,
-0.4 mm. Without hymenial algae. Sp. colorless
to slightly brownish, 60-120(150) x 20-50 µm
. Agonimia tristicula
6* Thallus brown, gray-brown, or olive-brown,
squamulose. Squamules 0.5-2.5(4) mm.
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