Which characteristic does a fragipan NOT display?

A fragipan is a specific soil layer that exhibits distinct physical characteristics which differentiate it from the layers above and below. One of the notable traits of a fragipan is its higher density compared to the surrounding soil layers. This higher density results from mineral cementation and compaction, which contributes to its unique physical properties.

Moreover, fragipans typically show evidence of pedogenesis, the process of soil formation, through features that indicate past environmental conditions and soil development. This includes characteristics such as structure, color, and alterations in texture due to biological and chemical processes over time.

Additionally, fragipans are known for their physical consistency; they can be cemented when dry, which makes them relatively hard, but when they become moist, they turn brittle, causing them to break apart easily. This transition in physical state further supports their unique classification within the soil profile.

In contrast, the characteristic of having roots distributed throughout the fragipan layer is not commonly observed. Roots tend to have difficulty penetrating this dense layer due to its compact nature, which makes it challenging for plant roots to grow through or establish themselves effectively. Thus, this aspect distinguishes the correct answer from the others, as it highlights a feature that fragipans generally do not support well.