KEY TO THE GENERA OF CRUSTOSE PYRENOCARPOUS LICHENS IN AUSTRALIA

Updated from Fl. Australia 58A: 197–206 (2001)

1

Thallus growing on fern fronds or on the leaves of shrubs or trees

2

1:

Thallus growing on bark or rock (rarely on soil, detritus or bryophytes)

13

2

Ascospores 1-septate

3

2:

Ascospores with 3 or more transverse septa, or submuriform to muriform

6

3

Ascomata pale greenish, partly covered by bundles of whitish hairs, 0.1–0.18 mm diam., hemispherical to subglobose, usually 1 per thallus; thallus small, smooth, continuous, roundish, pale greenish, often peeling; periphyses present; paraphysoids simple, entwined; asci thin-walled, clavate, 8-spored; ascospores 15–24 × 6–9.5 µm; distal cell shorter and more rounded

Porinella

3:

Ascomata dark brown to black

4

4

Thallus with shell-shaped short-stalked campylidia, epicuticular, growing on upper leaf surface, thin, greyish green, grey-brown or yellowish; ascomata c. 0.4–0.5 mm diam., dark brown to black, 1–several immersed in paler verrucae; ostioles separate or fused; ascospores slightly curved, 70–120 × 12–25 µm

Musaespora

4:

Thallus lacking campylidia

5

5

Paraphyses simple or sparingly branched, not anastomosing; thallus subcuticular, off-white, grey or green, sometimes with black dots or lines; photobiont Cephaleuros; ascomata usually convex, semi-immersed, with a black involucrellum (sometimes partly overgrown by the thallus), 0.2–0.5 (–1) mm diam.; ascospore cells usually equal, sometimes separating in the asci (those asci appearing 16-spored); conidia 0–1-septate, ellipsoidal

Strigula

5:

Paraphyses anastomosing; thallus epicuticular, greenish grey; photobiont ?Phycopeltis; ascomata hemispherical to subglobose, with a black involucrellum, 0.2–0.4 mm diam.; ascospores ovoid, 13–14.5 × 4.5–5.5 µm; distal cell larger; cells never separating; conidiomata with a black stellate apex and whitish subapical tissue; conidia simple, subglobose

Anisomeridium foliicola

6

Ascomatal apex disc-like, or with coarse papillae, warts or ridges; ascomata superficial, 0.2–0.7 mm diam., whitish, yellowish grey, grey or grey-brown; thallus whitish, grey, grey-green or green, diffuse, not rimose; photobiont a chlorococcoid alga; asci thick-walled, 2–8-spored; interascal hyphae unbranched; ascospores 10–30-septate or muriform

Aspidothelium

6:

Ascomatal apex smooth (if spiny, finely hairy or minutely irregular, then the ascus wall is uniformly thin-walled)

7

7

Ascospores with transverse septa only

8

7:

Ascospores muriform

12

8

Mature ascospores grey-brown, 3-septate, 9–13 × 3–4 µm; ascomata blackish, µconical, to 0.25 mm diam.; thallus thin, yellowish grey to greyish green or brown; photobiont Phycopeltis; asci 8-spored; interascal hyphae absent

Microtheliopsis uleana

8:

Mature ascospores colourless

9

9

Ascomata lacking interascal hyphae

10

9:

Ascomata with simple or sparingly branched interascal hyphae

11

10

Photobiont usually a unicellular chlorococcoid alga; thallus with or without minute globose isidia; perithecia hemispherical to subglobose, pale greenish, 0.15–0.2 mm diam.; involucrellum absent; periphyses present; ascospores 3-septate, 14–23 × 4–5 µm

Psoroglaena

10:

Photobiont usually a short-filamentous trentepohlioid alga; thallus pale grey to grey-green, usually without isidia, very thin, smooth; perithecia hemispherical to subglobose, 0.15–0.31 mm diam., µconcolorous with the thallus or orange-brown; involucrellum lacking; periphyses present; ascospores 3-septate and 14–26 × 3.5–5 µm or 7–15-septate and 39–68 × 4–6.5 µm

Pocsia

11

Ascomata with soft or stiff, radiating, oblique, horizontal or decurved subapical setae

Trichothelium

11:

Ascomata without setae

Porina

12

Ascomatal wall containing 4–6 ovoid structures, often in a star-shaped formation; perithecia greyish black, semi-immersed to superficial, 0.2–0.3 mm diam.; thallus very thin, pale grey; photobiont Trentepohlia; paraphyses unbranched; asci (2–) 4-spored; ascospores fusiform, 95–115 × 9–14 µm; pycnidia frequent, in groups of up to 50; conidia bacilliform, 3-septate

Phyllobathelium nigrum

12:

Ascomatal wall not containing ovoid structures; perithecia reddish brown to black, sessile, pyriform, 0.2–0.4 mm diam.; thallus very thin, pale greenish to dark grey-green, often black-speckled; paraphyses sparse or absent; asci 8-spored; ascospores elongate-cylindrical to µacicular, entwined in the ascus, c. 130–200 × 5–8 µm

Phylloblastia dolichospora

13

Ascospores simple, colourless

14

13:

Ascospores septate, colourless to dark brown

16

14

Ascomata pale, µconcolorous with the thallus, solitary, immersed in 0.35–0.5 mm diam. verrucae; thallus pale grey to bluish grey; interascal hyphae unbranched below, anastomosing towards the apices; asci 8-spored; ascospores 10–15 µm long, thin-walled

Monoblastia pellucida

14:

Ascomata µblack

15

15

Thallus saxicolous (very rarely terricolous); asci 8-spored; interascal hyphae absent; periphyses present

Verrucaria

15:

Thallus corticolous, granular, greenish; ascomata superficial, c. 0.5 mm diam., involucrellum absent; interascal hyphae present; periphyses absent; asci > 100-spored; ascospores globose, 2–3 µm diam.

Melanophloea pacifica

16

Interascal hyphae absent

17

16:

Interascal hyphae present

20

17

Ascospores mostly with 1–3 transverse septa

Thelidium

17:

ascospores muriform

18

18

Hymenium containing minute globose-cuboid or elongate algae

Staurothele

18:

Hymenium not containing algae

19

19

Exciple 3-layered; thallus minutely squamulose to granular, pale greenish brown; cortical cells papillose

Agonimia

19:

Exciple a single layer; thallus crustose to minutely granular, endolithic to superficial; cortical cells (when present) not papillose

Polyblastia

20

Mature ascospores brown

21

20:

Mature ascospores colourless (occasionally post-mature individuals brownish)

26

21

Ascospores granular-ornamented, pale brown, 1 (–3)-septate, rarely submuriform; thallus immersed, pale; ascomata flattened to subglobose; involucrellum black; interascal hyphae anastomosing

Mycomicrothelia

21:

Ascospores not granular-ornamented

22

22

Ascospores with transverse septa only

23

22:

Ascospores submuriform to muriform

24

23

Ascospores thin-walled, 1-septate; cells unequal; thallus immersed to superficial, continuous, lacking pseudocyphellae; ascomata solitary, semi-immersed to sessile, with a star-shaped ostiole; involucrellum black; interascal hyphae anastomosing; asci cylindrical to oblong

Asteroporum

23:

Ascospores thick-walled, 3 (–7)-septate; lumina lenticular, angular or rounded; thallus immersed to superficial, continuous to rimose, with or without pseudocyphellae; ascomata usually numerous, solitary or aggregated (then with or without fused ostioles), semi-immersed to superficial, blackish, with a thick often carbonised involucrellum, 0.2–2 mm diam.; interascal hyphae unbranched at maturity

Pyrenula

24

Thallus terricolous, grey-green, continuous to rimose; ascomata solitary, in immersed black 1–1.7 mm diam. pseudostromata; interascal hyphae anastomosing, not inspersed with oil globules; asci 1-spored; ascospores dark brown, muriform, 147–359 × 65–141 µm

Laurera robusta

24:

Thallus corticolous, pale grey, greyish green, grey-brown, yellowish brown or dark green, immersed to superficial, continuous to rimose, with or without pseudocyphellae; ascomata black, 0.15–2.5 mm diam., solitary or aggregated (then with fused ostioles), semi-immersed to superficial; interascal hyphae unbranched at maturity, often inspersed with oil globules; asci 2–8-spored; ascospores submuriform to muriform, 15–50 (–200) µm long

25

25

Ascospores thin-walled, dark brown at maturity; endospore poorly developed; lumina subcylindrical to µcuboidal; ascomata usually solitary, usually convex to subconical, otherwise hemispherical or subglobose, with a very hard brittle involucrellum or pseudostromatic shell

Anthracothecium

25:

Ascospores thick-walled, pale to dark brown at maturity; endospore usually well-developed; lumina lenticular, angular or rounded; ascomata solitary or aggregated (then with fused ostioles), with a thick carbonised involucrellum

Pyrenula

26

Asci containing 60–120 ascospores; thallus areolate, pale grey-brown; photobiont Trentepohlia-like; ascomata prominent, concolorous with thallus, 0.38–0.56 mm diam.; interascal hyphae simple; ascospores 1-septate

Thelopsis isiaca

26:

Asci containing (2–) 8 ascospores

27

27

Interascal hyphae simple or sparingly branched, not or scarcely anastomosing (only at the pase of the perithecium)

28

27:

Interascal hyphae anastomosing throughout or only towards their apices

32

28

Asci uniformly thin-walled

29

28:

Ascus wall uniformly quite thick or distinctly thicker near the apex, then the apex frequently dome-like with a convex, hemispherical or tuberculate inclusion (best seen in submature asci)

31

29

Thallus containing bright yellow or orange, erumpent crystals

Myeloconis erumpens

29:

Thallus lacking yellow and orange crystals

30

30

Perithecia lacking an involucrellum, pale orange brown, not immersed in thalline verrucae, 0.65–0.92 mm diam.; spores 122–230 × 26–42 µm, with 13–21 transverse septa

Amphorothecium

30:

Perithecia usually with a well-defined, black or reddish involucrellum, or perithecia immersed in thalline verrucae; spores usually less than 60 µm long

Porina

31

Perithecia whitish, yellowish grey, grey or grey-brown, with an apical disc-like expansion, sessile, 0.2–0.7 mm diam.; thallus whitish, grey, grey-green or green, diffuse, not rimose; photobiont chlorococcoid; asci 2–8-spored; interascal hyphae unbranched; ascospores 10–20-septate

Aspidothelium cinerascens

31:

Perithecia black, lacking any apical ornamentation or expansion, usually semi-immersed, c. 0.2–0.6 mm diam.; thallus immersed to superficial, usually predominantly grey; photobiont Trentepohlia; asci 8-spored; interascal hyphae simple or sparingly branched; ascospores 1–7-septate or submuriform

Strigula

32

Ascospores with transverse septa only

33

32:

Ascospores submuriform to muriform

43

33

Ascospores 1-septate

34

33:

Ascospores with 3 or more septa

36

34

Thallus or rock or soil; photobiont a cyanobacterium; thallus immersed and inconspicuous or superficial and greyish to almost black; ascomata black, immersed to superficial, 0.2–0.5 mm diam.; involucrellum present or absent; asci 4–8-spored, frequently broadly obovoid; interascal hyphae short-celled, richly anastomosing; ascospores 12–58 × 5–22 µm; distal cell usually larger

Pyrenocollema

34:

Thallus usually corticolous; photobiont Trentepohlia or absent

35

35

Perithecial wall cellular, not containing bark cells, blackish; ascomata convex to subglobose, c. 0.15–0.5 mm diam., interascal hyphae long-celled, anastomosing mainly towards the apices; asci cylindrical or cylindroclavate; ascospores without a perispore; thallus thin, immersed to superficial, continuous to rimose, pale grey, greenish grey or grey-brown

Anisomeridium

35:

Perithecial wall hyphal, containing bark cells, blackish; ascomata convex to hemispherical, c. 0.15–0.5 mm diam., interascal hyphae short- or long-celled, anastomosing throughout; asci obpyriform, obclavate or cylindrical; ascospores with or without a perispore; thallus thin, immersed, continuous, whitish, greenish grey to dark grey; photobiont Trentepohlia or absent

Arthopyrenia
s. lat.

36

Thallus saxicolous, pale olive-green; photobiont Trentepohlia; ascomata black, semi-immersed to µsuperficial, 0.23–0.35 mm diam.; interascal hyphae unbranched below, anastomosing towards their apices; asci 8-spored; ascospores 3-septate, 21–37 × 7–13 µm

Anisomeridium australiense

36:

Thallus corticolous or lignicolous

37

37:

Thallus whitish, cream or grey, sometimes with a greenish tint, ecorticate

38

37:

Thallus grey-green, green, yellow-brown, orange-brown or brown, corticate

40

38

Ascospores filiform, multiseptate, c. 60–140 × 1–2.5 µm, in fascicles or spirally arranged in narrowly cylindrical asci; ascomata solitary or in groups (covered by a common involucrellum, but with separate ostioles), circular to elongate, black, 0.4–1 mm wide; interascal hyphae anastomosing; photobiont Trentepohlia

Celothelium

38:

Ascospores narrowly ellipsoidal, clavate, fusiform or cylindrical, not filiform

39

39

Ascospores clavate, oblong or fusiform, usually constricted at the septa, 3-septate; ascomata convex to hemispherical, c. 0.15–0.5 mm diam.; perithecial wall blackish; interascal hyphae long- or short-celled, anastomosing throughout; asci obpyriform, obclavate or cylindrical; thallus endophloeodal, UV–; photobiont Trentepohlia or absent

Arthopyrenia
s. lat.

39:

Ascospores short- to elongate-cylindrical, 3–12-septate, not or scarcely constricted at the septa; ascomata hemispherical to subglobose, c. 0.2–0.6 mm diam.; perithecial wall blackish; interascal hyphae long-celled, loosely anastomosing; asci µcylindrical; thallus endophloeodal to thinly epiphloeodal, UV– or UV+ yellow; photobiont Trentepohlia

Polymeridium

40

Ascomata fused, with 3–6 locules opening via 1 or 2 ostioles; thallus epiphloeodal, continuous to sparingly rimose, verrucose, pale sandy brown, 60–120 µm thick, UV+ bright yellow; ascomata hemispherical, 0.8–1.5 mm diam., overgrown by the thallus, brown-black below, with yellow-orange crystals near the apex; asci 8-spored, with a flat broad ocular chamber; ascospores 3-septate, elongate-ellipsoidal, fusiform or subcylindrical, 21–26 × 6–8.5 µm, with polygonal lumina and a 3–5 µm thick perispore

Astrothelium galbineum

40:

Ascomata solitary or aggregated in raised and often pigmented pseudostromata; ostioles not fused

41

41

Pseudostromatal wall composed of brown convoluted hyphae (thin section); pseudostromata brown, usually glossy, containing yellow or orange pigments; ascospores 3–5-septate

Bathelium

41:

Pseudostromatal wall not composed of brown convoluted hyphae; pseudostromata not brown, dull to slightly glossy, usually not containing yellow or orange pigments; ascospores 3–15-septate

Trypethelium

42

Photobiont chlorococcoid; thallus membranous to rather thick and areolate, off-white, yellowish grey or green, grey-brown to olive-brown; ascomata concolorous with the thallus, or brownish to µblack, immersed to superficial, without (in Aust.) or with an involucrellum; asci 4–8-spored; periphysoids present or absent; mature ascospores colourless (in Aust.), rarely brown, ellipsoidal

Thelenella

42:

Photobiont Trentepohlia

43

43

Ostiole lateral, opening from a rather long neck; ascomata black, solitary, two-thirds immersed to almost superficial, ellipsoidal, 0.5–0.8 mm long; asci (4–) 8-spored; ascospores 33–55 × 13–22 µm; thallus very thin, ecorticate, pale grey to greenish grey

Polymeridium proponens

43:

Ostiole apical, not opening from a long neck

44

44

Pseudostromatal wall composed of brown convoluted hyphae (thin section); pseudostromata brown, usually glossy, containing yellow or orange pigments

Bathelium

44:

Pseudostromatal wall not composed of brown convoluted hyphae; pseudostromata not brown, dull to slightly glossy, usually not containing yellow or orange pigments

Laurera