| fasciation | a symptom characterized by fusing (and flattening) of such plant organs as stems. |
| fertile (stems) | capable of producing fruit and seed. |
| flag | the loss of rigidity and drooping of leaves and tender shoots preceding the wilting of a plant. |
| flagging | the loss of rigidity and drooping of leaves and tender shoots preceding the wilting of a plant. |
| flocked | covered with white cottony material so as appear like snow. |
| frass | solid larval insect excrement. |
| fruiting bodies | complex fungal structures containing spores. |
| fungal | referring to a group of saprophytic and/or parasitic organisms that lack chlorophyll and conductive tissues, and often produce spores. Includes molds, rusts, mushrooms, smuts, mildews, and yeasts. |
| fungi | saprophytic and/or parasitic organisms that lack chlorophyll and conductive tissues, and often produce spores. Includes molds, rusts, mushrooms, smuts, mildews, and yeasts. |
| fungus | a saprophytic and/or parasitic organism that lacks chlorophyll and conductive tissues, and often produces spores. Includes molds, rusts, mushrooms, smuts, mildews, and yeasts. |