Let me share with you a difference between crustose and fruticose lichens.
| Aspect | Crustose | Fruticose |
| Structure | Flat and closely attached to the substrate | Three-dimensional and often bushy or shrubby in appearance |
| Thallus | Thallus is crust-like and tightly adhered to the substrate | Thallus is more branching and may be erect or pendulous |
| Attachment to substrate | Tightly adheres to the substrate, like a crust | May attach loosely to the substrate or hang from it |
| Surface texture | Smooth or granular surface | May be smooth, wrinkled, or finely divided |
| Height | Low profile, usually close to the substrate | Can be raised above the substrate, extending into the air |
| Environmental adaptability | Often found in harsh or exposed environments | Can be found in a variety of habitats, including sheltered ones |
| Water absorption | Absorbs water mainly through the entire thallus surface | Water absorption primarily through the tips or outer parts |
| Sensitivity to environmental changes | More resistant to desiccation and environmental stress | May be more susceptible to desiccation and environmental changes |
| Common substrates | · Rocks · Bark · Soil | · Trees · Rocks · Soil |
| Growth rate | Generally slow-growing | Growth rate varies, can be slow to moderate |
| Examples | · Lecanora · Rhizocarpon | · Cladonia · Usnea · Evernia |