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- Megalosporaceae -
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Revised and updated key to Megalosporaceae (genera Austroblastenia, Megaloblastenia, Megalospora)
including some easily confused taxa
provisional version, by H. Sipman, 13 November 1997, corrected 22 Oct. 1999, partial revision 18 June 2017

This unpublished key is placed on the net as an update to the key in my monograph (Bibliotheca Lichenologica vol. 18, 1983).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:
Elix, J. A. 2009, The Megalospora melanodermia complex (Ascomycota, Megalosporaceae) in Australia. Australasian Lichenology 65: 20-23.
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.
Lücking, R. 2007: Megalospora imshaugii sp. nov. and M. caraibica sp. nov. from Jamaica (Ascomycota: Teloschistales: Megalosporaceae) increase the number of American Megalospora species to ten. Fungal Diversity 27: 103-110.
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 thickened                         3
 b    Spore septa and apical walls as thin as rest of wall           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     Sipmaniella sulphureofusca (Fée) Kalb 
                          syn. 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   Apothecium margin whitish and contrasting; hymenium 150-220 mu high;
spores 120-170 x 35-45 mu; New Guinea Megalospora granulans Sipman b Apothecium margin brownish, inconspicuous; hymenium c. 160 mu high;
spores 100-145 x 30-48 mu; New Zealand, Tasmania, New South Wales
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. with var. purpurea Elix, epithecium with scattered purplish,
K+ bluish crystals, absent in the main variety b Apothecia white-pruinose, at least when young, with scabrid discs M. galactocarpa (Zahlbr.) Elix 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 48 45a Epithecium olive-green 46 b Epithecium orange-brown 47 46a Apothecium white-pruinose; subhypothecium K-; Caribbean Megalospora imshaugii Lücking b Apothecium not pruinose; subhypothecium K+ blood-red; Caribbean Megalospora caraibica Lücking 47a 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 48a Apothecia soon convex, whitish pruinose; southern South America Megalospora kalbii Sipman b Apothecia flat slightly convex, epruinose or with thin bluish pruina 49 49a Apothecia flat to obconical; tropical America Megalospora admixta (Nyl.) Sipman b Apothecia flat; SW Australia Megalospora occidentalis Kantvilas


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page editor: Harrie Sipman, this page last updated 22 Oct. 1999, imprint
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