“Sedges have edges, Rushes are round, Grasses are Hollow, straight to the ground.”
Carex is the largest genus in the family Cyperaceae, containing around 2000 species globally. Commonly known as sedges they can be distinguished from grasses by their three-sided stems. You can feel the edges if your hold the stem between thumb and index finger and draw your hand up the stem. Botanists use the rhyme above to distinguish between sedges, rushes and grasses.
You are most likely to come across Carex species in wetland habitats. Interestingly Carex versicaria L. which is widespread with a circumpolar, boreo-temperate distribution has been used as thermal insulation in footwear by the Sámi people and for basket weaving in North America. We will come across this species later in the Carex expedition series.
The collections from Britain and Ireland held within the RBGE Herbarium are estimated to number over 500,000 specimens of cryptogams (algae, fungi, lichens and mosses), ferns, gymnosperms and flowering plants. We are in the process of digitising these collections, much of which has been carried out by volunteers who have taken part in our annual British DataBlitz, creating basic records for the specimens. We have then been able to use smaller funded projects to add images to these records.
The Royal Botanic Garden Edinburgh’s extensive Herbarium numbers nearly three million specimens representing half to two thirds of the world's flora. It is considered a leading botanical collection, and every year many researchers from around the world visit to study our specimens.