How do herbarium collections help scientists study the historical ranges of plants?

Herbarium collections, which are often housed within botanical gardens, serve as vital resources for scientists studying the historical ranges of plants. These collections consist of dried plant specimens that are collected in situ and mounted on archival paper, accompanied by detailed labels that record the specific location and date of collection.12

By analyzing the data associated with these specimens, researchers can document the historical biogeography of various species. Because some herbarium sheets date back hundreds of years, they provide a long-term record of where plants were once found, allowing scientists to track changes in distribution over time. This information is particularly valuable for:12

• Mapping historical ranges: Providing empirical evidence of where a species grew in the past.1
• Assessing biodiversity: Offering insight into the original biodiversity of habitats that may have since been degraded.2
• Tracing expeditions: Documenting the historical movements of plant collectors and explorers.1
• Locating rare species: Assisting in the identification and search for rare or endangered species.1