KEYS TO SOME COMMON GENERA OF MOULDS
1. Spores 1-celled 2
1. Spores with more than one cell 11
2. (1) Spores borne in dense masses within some kind of structure 3
2. Spores produced externally, never from any kind of compound structure 5
3. (2) Spores produced inside thin-walled sporangia that are recurved on short hooks
Compare with Mucor (Group I)
3. Spores never produced in recurved sporangia 4
4. (3) Fruiting structure a sporodochium containing a layer of conidiophores; spores in slimy masses, very dark green
4. Fruiting structure a cleistothecium containing asci (when young) and ascospores; spores dry at maturity; never associated with phialides
5. (2) Spores brown to black 6
5. Spores brightly coloured or colourless 8
6. (5) Spores roughened, with a prolonged apical snout; often associated with Cephalotrichum (Group II)
6. Spores smooth 7
7. (6) Spores usually borne in small clusters, usually egg- or bullet-shaped, with a narrow colourless band (germ slit); may be associated with Scopulariopsis (Group III)
7. Spores solitary, usually spherical to somewhat flattened spherical, often with a germ slit
8. (5) Conidiophores dark brown, densely branched at the apex and bearing the colourless spores in a drop of fluid
Compare with Phialocephala, Thysanophora, and Verticicladiella (not treated here)
8. Conidiophores colourless 9
9. (8) Spores completely covering a large swelling at the apex of an erect conidiophore
Compare with Cunninghamella
9. Conidiophores not well-developed and lacking a terminal swelling 10
10. (9) Spores relatively large, usually spherical, roughened
Several fungi produce large sphaerical scultured spores. Important among these are Histoplasma capsulatum and some Mortierella species. Histoplasma capsulatum is a serious human pathogen; if you believe that it is present in your culture, do not open the lid.
10. Spores quite small, usually egg-shaped, smooth; often causing skin infections in animals, including humans
11. (1) Spores dark (at least some of the cells) 12
11. Spores colourless 13
12. (11) Spores with long appendages at the apex, borne in sporodochia
12. Spores lacking appendages, not in sporodochia
Compare with Paradendryphiella
13. (11) Spores 2-celled, produced in chains from the apex of erect conidiophores
13. Spores usually with more than 2-cells or irregularly 1- to several-celled, not arising from distinct conidiophores; often causing skin infections in animals, including humans
Compare with Microsporum