Dichotomous Keys

1. Conidiophores dark brown; conidia ellipsoidal ……………..…………………..……….…….….. 2
1’. Conidiophores pale brown; conidia obclavate to pyriform …………………………..…….……. 4

2. On Musa or Canna ……..………………………………………………………….…… Neocordana
2’. On Poaceae……………………………………………………………………………………..……. 3

3. Conidiophores flexuous, long, dark brown; conidiogenous cells terminal and intercalary;
conidia pale brown, 2-septate; on Sasa sp. and Phyllostchys bambusoides …… Bambusicularia
3’. Conidiophores solitary, simple, short; conidiogenous cells percurrently rejuvenating;
conidia 1-2-septate; on leaves of Phragmites ……….…………………………….…….. Utrechtiana

4. On Poaceae …………………………………..………………….……………..…………………….. 5
4’. On other monocots ………………..………………………………………………..……..….…….. 6

5. Conidiophores cylindrical, unbranched; conidiogenous cells terminal and intercalary, with
flat denticles with a central pore …………………………………………. Pyricularia (Type genus)
5’. Conidiophores flexuous, branched, conidia obovoid; on Zizania latifolia ……. Xenopyricularia

6. Conidiogenous cells integates terminal, on Asarum ……………………………Pyriculariomyces
6’. not as above……………………………………………………………………………………………. 7

7. Conidiogenous cells terminal forming a rachis with densely protruding denticles ………..…… 8
7’. Conidiogenous cells terminal and intercalary with sparsely protruding denticles …………….. 10

8. Conidiogenous cells cylindrical denticles; conidia hyaline to pale brown with darker colored
median cell; conidiogenous cells terminal and intercalary; on leaves of Calathea longifolia ………
…………………………………………………………………………………………….…….. Barretomyces
8’. Conidiogenous cells terminal with flat denticles ……………………….…………….………..….. 9

9. Conidia narrowly obclavate, 1-septate; on leaves and stems of Juncus effuses ………..………
…………………………………………………………………………………..…..……… Macgarvieomyces
9’. Conidiophores short; conidia 2-septate; on Cyperus rotundus, Typha orientalis, and Kyllinga
brevifolia ……………………………………………………………………..…….….. Pseudopyricularia

10. Conidiophores olivacous; on leaves of Commelina communis ………….…….. Neopyricularia
10’. Conidiophores olivacous to medium brown; on Zingiber mioga ………….…. Proxipyricularia

Copyright 2022 by The American Phytopathological Society. Reproduced, by permission, from Luo, J., and Zhang, N. 2022.  The Rice Blast Fungus and Allied Species: A Monograph of the Fungal Order Magnaporthales (https://my.apsnet.org/APSStore/Product-Detail.aspx?WebsiteKey=2661527A-8D44-496C-A730-8CFEB6239BE7&iProductCode=46826). American Phytopathological Society, St. Paul, MN.

1. In aquatic habits generally ……………………………….……….…………….……………….. 2
1’. In terrestrial habits generally; ascospore fusiform ………………………………………….… 3

2. Ascomata dark brown to black, with a single ascus discharged through the ascomatal neck
……………………………………………………………………………………….. Ophioceras (Type genus)
2’. Ascomata yellow to brown, membranous, with ascospores amassing at the ascomatal neck
…………………………………………………………………………………………………. Pseudohalonectria

3. Ascomata immersed, solitary or in small groups ………………………………………………..
……………………………………………………………………………………………………………………………. 4
3’. Ascomata superficial, gregarious in large clusters with a basal stroma, dark brown ……….
…………………………………………………………………………………………………….. Ceratosphaerella

4. Ascomata yellow brown; ascospores fusiform; on wood ………………..… Ceratosphaeria
4’. Ascomata dark brown; ascospores filiform; on dead leaves of Magnolia …..………………….
……………………………………………………………………………………………………….Tropohalonectria

Copyright 2022 by The American Phytopathological Society. Reproduced, by permission, from Luo, J., and Zhang, N. 2022. The Rice Blast Fungus and Allied Species: A Monograph of the Fungal Order Magnaporthales (https://my.apsnet.org/APSStore/Product-Detail.aspx?WebsiteKey=2661527A-8D44-496C-A730-8CFEB6239BE7&iProductCode=46826). American Phytopathological Society, St. Paul, MN.

1. Asexual state absent or unknown ……………………………………………………………….……. 2
1’. Asexual state present ………………………………………………………….………………..…….. 6

2. In aquatic habits; ascospores aseptate; on wood ……………….….………..…… Aquafiliformis
2. In terrestrial habits; ascospore septate …………………………………………………….………… 3

3. Ascomata superficial, collapsing when dry; ascomatal wall with a vacuolated middle layer; on
bark or wood …………………………………………………………………….………..……. Muraeriata
3. Not as above………………………………………………………………………….………..…..……. 4

4. Ascomata immersed without a protruding neck; ascospores clavate with basal septa and an
apical mucilaginous pad-like appendage; on leaves of Musa sp. ………………….. Clavatisporella
4’. Ascomata immersed, with a long cylindrical neck ……………………………………….…………. 5

5. Ascomata solitary; ascospores 5-septate, yellowish brown with paler end cells; on Carex firma
and Sesleria varia……………………………………………………………….………….. Herbampulla
5’. Ascomata gregarious on a mycelial subiculum; ascospores filiform, 2-3-septate; on culms of
Bambusa sp. ………………………………………………………………..…. Neogaeumannomyces

6. Asexual state with pycnothyrial conidiomata …………………………………….… Pseudotracylla
6’. Not as above ……………………………………………………………………………..……………… 7

7. Ascomata developing amongst a setose mycelium; asexual state Clasterosporium, conidia
elongated and strongly pigmented ……………………………………………….…… Clasterosporium
7’. Not as above ………………..……………………………………………………………………………. 8

8. Ascomata with a long cylindrical neck; ascospore indistinctly septate; asexual state
trichocladium-like; on Juncus sp. …………………………………………………….. Kohlmeyeriopsis
8’. Not as above ………………………………………………………………………………….…………. 9

9. Ascomata with a long cylindrical neck; ascospore funsiform; asexual state mycoleptodicsus-like
……………………………………………………………………………..…………………. Omnidemptus
9’. Not as above …………………………………………………………………..………………………. 10

10. Ascomata with a long neck; ascospore 3-septate; asexual state Nakataea, conidia falcate,
3-septate with darker median cells; a sclerotium state present …………. Nakataea (Type genus)
10’. Not as above …………..…………………………………………………………………….………. 11

11. Asexual state pyricularia-like ……………………………….……………………..……………….. 12
11’. Asexual state phialophora-like ……………………………………………..……………………… 14

12. Ascomata papillate; ascopsore clavate ………………………………….………… Buergenerula
12’. Not as above ……………………….……………………………………………………………….. 13

13. Conidiophores unbranched; conidia pale brown and 4(-5)-septate ………. Bussabanomyces
13’. Conidia 3-septate with darker median cells ………………………..………….. Pyriculariopsis

14. Conidiophores simple or slightly branched; conidia ellipsoidal …………………………….….. 15
14’. Not as above …………………………………………….………………………………………….. 18

15. Ascospores ellipsoidal, 3-septate, with dark brown and striate central cells, and pale brown
and smooth apical cells ……………………………………………………….…. Budhanggurabania
15’. Not as above …………………………………………….………………….…………….………… 16

16. Colonies slow-growing on PDA (diameter < 30 mm after 7 days at 25 C), conidiophores
curved ………………………………………………………………………..……….. Pseudophialophora
16’. Colonies fast-growing on PDA (diameter ≥ 30 mm after 7 days at 25 C), conidiophores
straight ……………………………………………………………………………………………………… 17

17. Conidiogenous cells with a conspicuous collarette; conidia fusiform; from soil…………………
……………………….……………………………………………………………….…………… Faciphoriella
17’. Conidiogenous cells without conspicuous collarette; conidia obovoid; on roots of Poaceae…
………………………………………………………………..……………….………… Magnaporthiopsis

18. Conidiophores complex, branched; Conidia strongly curved and sickle-shaped …………… 19
18’. Conidiophores and conidia dimorphological; conidiophores simple to complex ……….….. 20

19. Conidiogenous cells with a conspicuous collarette; on roots of Oryza sp. ……….. Falciphora
19’. Conidiogenous cells without a conspicuous collarette; on Carex rostrata ………………………
…………………………………………………………………………………….……..…Gaeumannomycella

20. Conidia falcate, straight to slightly curved ……………………………….………. Bifusisporella
20’. Conidia ellipsoidal to sickle-shaped …………………………………………..………………… 21

21. Ascomata immersed; Ascospores hyaline, filiform; pathogenic to cereals and grasses ……
……………………………………………………………………………..………… Gaeumannomyces
21’. Ascomata superficial and hairy; ascospores fusoid; non-pathogenic to cereals and grasses
……………………………………………………………………………….………….… Slopeiomyces

Copyright 2022 by The American Phytopathological Society. Reproduced, by permission, from Luo, J., and Zhang, N. 2022. The Rice Blast Fungus and Allied Species: A Monograph of the Fungal Order Magnaporthales (https://my.apsnet.org/APSStore/Product-Detail.aspx?WebsiteKey=2661527A-8D44-496C-A730-8CFEB6239BE7&iProductCode=46826). American Phytopathological Society, St. Paul, MN.

1. Saprotrophic on plant debris, barks, or wood generally …………………………… Ophioceraceae
1’. Pathogenic or endophytic in monocotyledonous plants generally ………………………………….. 2

2. Infecting host above-ground tissues using appressoria typically; asexual state pyricularia-like
typically ……………………………………………………………………………………………….. Pyriculariaceae
2’. Infecting host root tissues using hyphopodia typically; asexual state phialophora-like typically
………………………………………………………………………………………………………… Magnaporthaceae

Copyright 2022 by The American Phytopathological Society. Reproduced, by permission, from Luo, J., and Zhang, N. 2022.The Rice Blast Fungus and Allied Species: A Monograph of the Fungal Order Magnaporthales (https://my.apsnet.org/APSStore/Product-Detail.aspx?WebsiteKey=2661527A-8D44-496C-A730-8CFEB6239BE7&iProductCode=46826).American Phytopathological Society, St. Paul, MN.