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- Megalosporaceae -
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Revised key to Megalosporaceae (genera Austroblastenia, Megaloblastenia, Megalospora)
including some easily confused taxa
provisional version, by H. Sipman, 13 November 1997, corrected 22 Oct. 1999

This unpublished key is placed on the net as an update to the key in my monograph (Bibliotheca Lichenologica vol. 18, 1983). Comments are very welcome.

References:
Kalb, K. 1990. Schedae for Lichenes neotropici Fasc. XI (No. 451-475). 12 pp. Neumarkt/Opf.
Kantvilas, G. 1994. Additions to the family Megalosporaceae in Tasmania and mainland Australia. Lichenologist 26: 349-366.
Sipman, H.J.M. 1983. A monograph of the lichen family Megalosporaceae. Bibliotheca Lichenologica 18: 1-241.
Sipman, H.J.M. 1986. Additional notes on the lichen family Megalosporaceae. Willdenowia 15: 557-564.


1a    Spores uniseptate                                              2
 b    Spores pluriseptate, bacillar                                 26
 c    pluriseptate, muriform                                        42

2a    Spore septa and apical walls thick                             3
 b    Spore septa and apical walls thin                              5

3a (2) Thallus whitish grey, P+ orange, KC- (pannarin); apothecia more 
      or less grey-pruinose; Australasia, Tropics
            Megaloblastenia marginiflexa (Hook. & Tayl.) Sipman .....4
 b    Thallus yellowish grey, P-, KC+ yellow (usnic acid); apothecia 
      black; New Zealand, Tasmania
                             Megaloblastenia flavidoatra (Nyl.) Sipman

4a    Subhypothecium dark brown; Australia, New Zealand, New Guinea
                                     M. marginiflexa var. marginiflexa
 b    Subhypothecium pale; tropical America
                            M. marginiflexa var. dimota (Malme) Sipman

5a    Spores always single in each ascus, straight, elongate, usually 
      3 or more times as long as wide; hymenium guttulate; widespread
                                                                     6
 b    Spores with 2 in each ascus, straight; hymenium clear; 
      Neotropical          Lopezaria versicolor (Fée) Kalb & Hafelln.
 c    Spores with (1-)2-8 in each ascus, usually curved and less than 
      3 times as long as wide; hymenium guttulate; widespread in the 
      Tropics and Australasia                                       19

6a    Thalline margin present; hymenium 85-120 mu high, I+ deep blue 
      throughout; Neotropics
                             "Lecania" sulphureofusca (Fée) Müll. Arg.
 b    Thalline margin absent; hymenium (100-)120-180(-230) mu high, I- 
      except around the asci; Palaeotropics, Australasia             7

7a    Thallus whitish, P+ orange, KC- (pannarin)
                     Megalospora gompholoma (Müll. Arg.) Sipman .....8
 b    Thallus yellowish, P-, KC+ yellow (usnic acid)                 9

8a    Orange-brown layer present below the hymenium (observe with 
      incumbent light); New Zealand      M. gompholoma ssp. gompholoma
 b    Dark brown layer present below the hymenium; Australia, 1x New 
      Zealand                   M. gompholoma ssp. fuscolineata Sipman

9a    Soredia present                                               10
 b    Soredia absent                                                12

10a   Soredia granular, scattered usually over most of the thallus; 
      apothecium margin yellowish                                   11
  b   Soredia farinose, mostly restricted to punctiform soralia; 
      apothecium margin black; Japan
              Megalospora atrorubicans (Nyl.) Zahlbr. ssp. sendaiensis

11a   Hymenium 150-220 mu high; spores 120-170 x 35-45 mu; New Guinea
                                          Megalospora granulans Sipman
  b   Hymenium c. 160 mu high; spores 100-145 x 30-48 mu; New Zealand, 
      Tasmania                            Megalospora disjuncta Sipman

12a   Isidia present; New Zealand        Megalospora bartlettii Sipman
  b   Isidia absent                                                 13

13a   Spores under 100 mu long                                      14
  b   Spores over 100 mu long                                       18

14a   Apothecium margin yellowish; New Caledonia
                               Megalospora sulphureorufa (Nyl.) Riddle
  b   Apothecium margin brown to black                              15

15a   Apothecia with conical lower side, narrowest at the attachment; 
      New Caledonia                          Megalospora hillii Sipman
  b   Apothecia with flat lower side
                       Megalospora atrorubicans (Nyl.) Zahlbr. .....16

16a   Apothecium margin black, in older apothecia disappearing; Asia, 
      North America     M. atrorubicans ssp. sendaiensis (Räs.) Sipman
  b   Apothecium margin pale to black, persistent                   17

17a   Thin orange-brown layer present below the hymenium (observe with 
      incumbent light); apothecia usually over 1 mm wide; New Zealand, 
      Australia                  M. atrorubicans ssp. australis Sipman
  b   No such layer present; apothecia usually under 1 mm wide; 
      palaeotropical                 M. atrorubicans ssp. atrorubicans

18a   Apothecia with conical lower side, narrowest at the attachment; 
      New Guinea                             Megalospora weberi Sipman
  b   Apothecia with flat lower side                                17

19a   Thallus whitish, P+ orange, KC- (pannarin)                    20
  b   Thallus yellowish, P-, KC+ yellow (usnic acid)                21

20a   Thallus esorediate; New Zealand
                             Megalospora campylospora (Stirton) Sipman
  b   Thallus entirely coarsely granular sorediate; Tasmania
                                       Megalospora pulverata Kantvilas

21a   All spores under 45 mu long                                   22
  b   Most or all spores over 45 mu long                            24

22a   Soralia present, 0.5-1 mm wide; New Zealand, Australia
                            Megalospora subtuberculosa (Knight) Sipman
  b   Soralia absent; Australia                                     23

23a   Apothecia persistently epruinose, with glossy discs
       Megalospora melanodermia (Müll. Arg.) Zahlbr. var. melanodermia
  b   Apothecia white-pruinose, at least when young, with scabrid 
      discs      M. melanodermia var. galactocarpa (Zahlbr.) Kantvilas

24a   Epithecium with thick, granular layer which penetrates up to 70 
      mu into the hymenium; New Zealand    Megalospora knightii Sipman
  b   Epithecium without granules
                                  Megalospora sulphurata Meyen......25

25a   Epithecium orange-brown to brown; Palaeotropics
                                         M. sulphurata var. sulphurata
  b   Epithecium olive-green to olive-brown or dark brown; Neotropics, 
      Africa          M. sulphurata var. nigricans (Müll. Arg.) Riddle

26a(1) Spores single in each ascus, straight                        27
  b   Spores 2-8 per ascus, mostly curved                           34

27a   Thallus whitish grey, P+ orange, KC- (pannarin)               28
  b   Thallus yellowish grey, P-, KC+ yellow (usnic acid)           33

28a   Soredia present                                               29
  b   Soredia absent                                                30

29a   Soralia white; Great Lakes area of North America
                          Megalospora porphyrites (Tuck.) R. C. Harris
  b   Soralia yellow; Neotropics   Megalospora chloritis (Tuck.) INED.

30a   Spores over 150 mu long; New Guinea
                                          Megalospora albescens Sipman
  b   Spores usually under 100 mu long                              31

31a   Algae present in the apothecium margin (in ectal excipulum); 
      Australia          Megalospora australiensis (Müll. Arg.) Sipman
  b   No algae present in the apothecium margin                     32

32a   Apothecia ± concave with inflexed, bluish margin; Australia
                                   Megalospora inflexa (Knight) Sipman
  b   Apothecia plane to convex, with more or less prominent, pale 
      brown to black margin; subcosmopolitic
                                  Megalospora tuberculosa (Fée) Sipman

33a   Hymenium over 200 mu high; excipulum in section K+ yellow; SE 
      Asia                                    Megalospora halei Sipman
  b   Hymenium under 200 mu high; excipulum in section usually K-;     
      subcosmopolitic             Megalospora tuberculosa (Fée) Sipman

34a   Thallus whitish grey, P+ orange, KC- (pannarin) or P-, KC- 
      (lichexanthone)                                               35
  b   Thallus yellowish grey, P-, KC+ yellow (usnic acid)           41

35a   Spores with thick septa with clear pores, always three-septate, 
      35-40 mu long      Austroblastenia pauciseptata (Shirley) Sipman
  b   Spores with thin septa without clear pores, usually 5-11-
      septate, over 60 mu long                                      36

36a   Apothecium margin pale; spores 70-105 mu long                 37
  b   Apothecium margin dark brown to black; spores 90-140 mu long 
                     Megalospora pruinata (Müll. Arg.) Sipman.......39

37a   Hymenium 105-180 mu high; lichexanthone present (UV+ orange); 
      Neotropics                Megalospora pachycheila (Tuck.) Sipman
  b   Hymenium 200-280 mu high; pannarin present (UV- or + white)
                            Megalospora coccodes (Bél.) Sipman......38

38a   Upper part of ectal excipulum with white, elongate, c. 4 x 1 mu 
      large crystals; SE Asia
                        M. coccodes ssp. nigricans (Müll. Arg.) Sipman
  b   Upper part of ectal excipulum with tiny yellowish crystals; 
      Africa and America                     M. coccodes ssp. coccodes

39a   Hymenium under 220 mu high; Africa     M. pruinata ssp. pruinata
  b   Hymenium over 220 mu high                                     40

40a   Apothecia black, sometimes with a bluish-white pruina; 
      Indonesia, Malaya, Sabah
                               M. pruinata ssp. lamii (Groenh.) Sipman
  b   Appothecia very dark brown, sometimes with a slight grey pruina; 
      New Guinea                         M. pruinata ssp. fusca Sipman

41a   Apothecium margin brown to black; spores with completely thin 
      septa; W. Africa             Megalospora thomensis (Nyl.) Sipman
  b   Apothecium margin pale yellowish; spores with thick rings along 
      the attachment lines of the septa with the outer wall; Madeira
                             Megalospora maderensis (Krempelh.) Sipman

42a (1) Spores with thick transverse septa, 4-8 per ascus; New Zealand, 
      Tasmania                             Austroblastenia pupa Sipman
  b   Spores only with thin septa, solitary in each ascus; widespread
                                                                    43

43a   Thallus whitish grey, P+ orange, KC- (pannarin); spores 60-105 
      mu long                                                       44
  b   Thallus yellowish grey, P-, KC+ yellow (usnic acid); spores 80-
      125 mu long; Queensland         Megalospora queenslandica Sipman

44a   Apothecia dark brown to black, large, usually 1.5-2 mm wide   45
  b   Apothecia pale brown to brown, usually small, 0.7-1.3(-2) mm 
      wide                                                          46

45a   Apothecium margin black; spores 60-90 mu long; Tasmania
                                        Megalospora lopadioides Sipman
  b   Apothecium margin pale brown; spores 80-110 mu long; Neotropics
                                            Megalospora foersteri Kalb

46a   Apothecia soon convex, whitish pruinose; southern South America
                                             Megalospora kalbii Sipman
  b   Apothecia flat slightly convex, epruinose or with thin bluish 
      pruina                                                        47

47a   Apothecia flat to obconical; tropical America
                                     Megalospora admixta (Nyl.) Sipman
  b   Apothecia flat; SW Australia
                                    Megalospora occidentalis Kantvilas


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© Botanischer Garten und Botanisches Museum Berlin-Dahlem, Freie Universität Berlin
page editor: Harrie Sipman, this page last updated 22 Oct. 1999, imprint
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