Carex acuta - Acute Sedge

The Carex acuta, also known as the Sharp-Edged Sedge, a plant related to grasses, is found along the water's edge in our marshes, throughout France, and especially in the central and northeastern regions. This medium to large-sized perennial forms a clump of evergreen, very fine, bluish-green leaves and produces beautiful cylindrical spikes of dark brown flowers, between May and August. This carex is planted on the edge of a water point for its qualities as a bank stabilising plant. It can also be used for its purifying qualities in a phytoremediation pond. It requires no maintenance.

The Carex acuta belongs to the Cyperaceae family. Native to Eurasia, it is found almost everywhere in the world. This rhizomatous plant, similar in appearance to grasses, with running rhizomes, forms an upright and arching clump, reaching a height of 50 to 80 cm and a diameter of about 40 cm, spreading over time to form large colonies in moist or waterlogged soils. This species grows at a depth ranging from 0 to -5 cm of water. Its leaves, evergreen in winter, sheath-like at the base, are long, slender (4 to 8 mm wide), linear, with tapered edges, slightly trailing. They have a bluish-green colour. The older leaves dry out in winter to make way for new leaves in spring. In spring, in April-May depending on the climate, floral stems appear bearing male or female spikes. The male spikes, thick, cylindrical-elliptical, dark brown, barely emerge from the foliage and are quite decorative. As with all Carex species, it is monoecious, producing separate male and female flowers on the same individual.

The Carex acuta can be planted in any type of wet area, in full sun or partial shade. Useful for maintaining banks or for its purifying qualities, it can also be planted for its ornamental value on the edge of a pond. In the company of other bank plants, equally decorative, such as Acorus, Cirsium rivulare or purple plume thistle, Butomus umbellatus or flowering rush, Alisma parviflora, or even Caltha palustris.