Bryochiton perpusillus

Hosts: Polytrichaceae; most frequently Polytrichum piliferum. Also recorded on leafy liverworts, including Ptilidium ciliare, P. pulcherrimum, Porella sp. and Barbilophozia s.l.

Blackish ascomata erupting from the abaxial leaf cuticle of Polytrichum piliferum (Austria).
Material on Polytrichum formosum (1000X) from Merionethshire, Wales. Sept 2021
Material from Polytrichum piliferum on sandy soil (Ventnor Down, Isle of Wight, Aug 2018). Micrographs of material mounted in LCB at 1000X.
Vegetative hyphae at 1000X in lactophenol cotton blue. Material from Ventnor Down, Aug 2018
Ascus and ascospores of Austrian material in water.

Simplified key to the four described Bryochiton species, adapted from Döbbeler (1978). I choose to use ascospore morphology as the chief ID determinant to encourage searching for fruitbodies over merely recording from vegetative hyphae, especially for material on Polytrichum. Host specificity is not strict for B. monascus and B. perpusillus.

1a. Spores 1-septate...................................2a

1b. Spores 2- or 3-septate.............................3a

2a. Spores fusiform, on Gymnomitrion.....B. microscopicus

2b. Spores ellipsoidal with rounded ends, on
    Polytrichaceae and various leafy 
    liverworts.............................B. perpusillus

3a. Spores 2-septate, on Polytrichastrum 
    sexangulare..........................B. heliotropicus

3b. Spores 3-septate, on Grimmiaceae or 
    Polytrichaceae............................B. monascus

References

  • Döbbeler, P. (1978). Moosbewohnende Ascomyceten I. Die pyrenocarpen, den Gametophyten besiedelnden Arten. Mitt. Bot. Staatssamml. München, 14: 1-360