Calcium-rich exposed substrates are considered to be uncommon in South Carolina, where low pH readings are also the rule. Field data indicate that the calcium rich substrates can be recognized by calcium-indicator plants. The calcium-rich habitats and plant communities include mountain and piedmont marble outcrops and basic forest, and coastal plain calcareous cliffs and calcareous floodplains. These communities are defined. Nineteen selected calciphiles in the region are suggested for further study for inclusion on the South Carolina Heritage Program’s list of plant species of concern. Sixty-one calcium-indicators are listed for the Calcareous Cliff community, fifty-seven for the Calcareous Floodplain community, and forty-eight for mountain and piedmont calcareous habitats. The occurrence of listed plants can be used to predict calcareous substrate types in the region and may be useful as a guide for the cultivation requirements of these plants.