Aspergillus Species: Conidial Head Comparison
Original bench-card visual comparing Aspergillus conidial heads: fumigatus compact columnar, niger biseriate radiate, flavus variable, and terreus with accessory aleurioconidia.
Aspergillus comparison: head shape and seriation across four species
These four share septate acute-angle hyphae. Separate them by conidial head shape and seriation, not by hyphae. Keep species claims tied to culture morphology and validated workflow.
Compact columnar head with phialides over the upper vesicle only (uniseriate). Conidia column points upward. Tolerates higher temperatures.
Look for a large radiate conidial head with dark conidia and biseriate structures around the vesicle.
Radiate head that may be uniseriate, biseriate, or both. Conidiophore wall is rough. Colonies are often yellow-green.
Small compact columnar biseriate head, plus accessory aleurioconidia borne singly on the hyphae. The accessory conidia are the terreus clue.
Compact columnar head with phialides over the upper vesicle only (uniseriate). Conidia column points upward. Tolerates higher temperatures.
Look for a large radiate conidial head with dark conidia and biseriate structures around the vesicle.
Radiate head that may be uniseriate, biseriate, or both. Conidiophore wall is rough. Colonies are often yellow-green.
Small compact columnar biseriate head, plus accessory aleurioconidia borne singly on the hyphae. The accessory conidia are the terreus clue.
Aspergillus comparison anchors
| Visual clue | Meaning | Student shorthand |
|---|---|---|
| Compact columnar, uniseriate | A. fumigatus pattern | Phialides on the upper vesicle only; thermotolerant |
| Radiate biseriate, dark conidia | A. niger pattern | Full sphere head; black colonies |
| Radiate, variable seriation, rough stalk | A. flavus pattern | Uni- or biseriate; yellow-green colonies |
| Compact biseriate plus aleurioconidia | A. terreus pattern | Accessory hyphal conidia are the key separator |
Aspergillus comparison interpretation guide
| Pattern | What to call it | How to think about it |
|---|---|---|
| Compact columnar uniseriate head | A. fumigatus group | Confirm with culture morphology and validated workflow |
| Radiate biseriate head, dark conidia | A. niger group | Correlate with black colony color |
| Radiate variable head, rough stalk | A. flavus group | Correlate with yellow-green colony color |
| Compact biseriate head plus aleurioconidia | A. terreus group | Look for accessory hyphal conidia |
- Aspergillus species share hyphae but differ in conidial head structure.
- Track head shape, seriation, stalk texture, and accessory conidia together.
- Keep species-level identification tied to culture morphology and validated methods.
fumigatus compact columnar, niger radiate dark, flavus rough variable, terreus aleurioconidia.