Cladium mariscus aka Swamp Sawgrass

Cladium mariscus is a perennial sedge in the Cyperaceae family. Gardeners may know it as great fen-sedge or elk sedge. The RHS also lists the Welsh name corsfrwynen lem. An older scientific name is Schoenus mariscus. Its native range spans the Americas, Azores, and temperate Eurasia. It also includes North Africa, Australia, and the southwest Pacific. The RHS records it as native to Britain and Ireland. Kew places the species in temperate climates.

This sedge grows in fens and swamps among reeds. It can form thick stands with few other plants mixed in. These wild sites tend to have neutral or alkaline soil. That habitat helps explain its need for wet ground in gardens. The supplied species-level evidence gives no mature height or spread. It also gives no clear account of leaves, stems, flowers, or fruit. Those details cannot be drawn from the related sawgrass subspecies.

Plants For A Future reports that it grows in wet soils. Soil that holds moisture can also suit the plant. The source does not limit it to one soil texture. It accepts full sun as well as some shade. Its recorded habitat points to neutral or alkaline ground. The cultivation note puts more weight on moisture than soil type. Plants For A Future lists USDA hardiness zones 3 through 7. The supplied RHS text gives no UK hardiness rating.

Its documented uses include roof thatch and small woven baskets. People have used the stems as a roof covering. They have also used the roots to make small baskets. Plants For A Future gives these uses a low rating. Its ability to form dense stands is worth noting when planning space. The same source does not flag it as a weed. The evidence does not establish a growth rate or care difficulty. It names no pests or diseases for this species.

Plants For A Future lists leaves and shoots as edible parts. Its note treats young shoots as a possible food source. That wording leaves some doubt about their use as food. The site's edible-use rating is just one out of five. It records no known medicinal use and no known hazards. This does not provide a separate safety assessment for pets. Nor does it establish that every plant part is safe to eat.