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KEYS TO SOME COMMON GENERA OF MOULDS

GROUP IV

1. Spores 1-celled 2

1. Spores with more than one cell 11

2. (1) Spores produced within a distinct fruiting body having a hyphal or cellular wall 3

2. Spores borne externally 6

3. (2) Fruiting bodies or spore mass brown or black 4

3. Fruiting bodies and spore mass colourless or brightly coloured 5

4. (3) Spores brown; fruiting bodies (pycnidia) lacking spines

Microsphaeropsis

Compare with Myrothecium (Group V)

4. Spores colourless or brightly coloured; fruiting bodies (pycnidia) with spines around the apical opening

Pyrenochaeta

5. (3) Fruiting bodies (cleistothecia) composed of hyphae; usually with an abundant brush-like anamorph

Talaromyces

Compare with Gymnoascus (Group V) and Arachniotus (not treated here)

5. Fruiting bodies (cleistothecia) with a distinctly cellular wall; usually with a conspicuous anamorph characterized by bottle-shaped philides borne on a swollen apical vesicle

Teleomorphs of Aspergillus

Species of Penicillium may have similar teleomorphs.

6. (2) Spores distinctly dark brown or black 7

6. Spores colourless or quite pale 8

7. (6) Spores usually spherical and roughened, with two hyphal connections; hyphae mostly not septate

Zygospores of Mucorales

Usually associated with Absidia, Mucor, Rhizopus, Zygorhynchus (similar to Mucor), etc. Read about Zygosporangia for a more detailed discussion of how these structures are formed.

7. Spores discoid or egg-shaped, often with a colourless band, usually smooth, with only one connection to the conidiophore; hyphae septate

Arthrinium

Compare with Wardomyces and Nigrospora (both Group V)

8. (6) Spores in chains (sometimes interrupted by sterile cells) 9

8. Spores not in chains 10

9. (8) Spore chains often characterized by an alternating series of spores and narrow sterile cells (bead-like in appearance); filaments never dark

Geomyces

Compare with Chrysosporium (Group II)

9. Spore chains composed of uniformly cylindrical spores, never with alternating sterile cells; conidiophores often dark

Oidiodendron

10. (8) Spores borne from the apex of flask-shaped phialides with a flaring collar

Phialophora

Compare with Exophiala (Group III)

10. Spores borne at the tips of somewhat jagged conidiophores

Sporothrix

11. (1) Spores borne in fruiting bodies (pycnidia), 2-celled

Diplodia

11. Spores borne externally, with more than two cells

Pithomyces

Compare with Trichocladium (Group V)

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