- Scientific name: Carex striata
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
- Endangered (MA Endangered Species Act)
Description
Walter's sedge, a variety of the species Carex striata, is a pale-green, narrow-leaved, grass-like perennial that often forms extensive colonies. The sharply angled stems, or culms, rise from long, slender rhizomes and reach from 4-12 dm (1-4 ft) in height. The principal leaf blades are stiff and 2-5 mm (0.08 - 0.2 in) wide. Like most members of the sedge family (Cyperaceae), Walter’s sedge lacks showy floral parts. Each culm bears two or more spikes (elongate, unbranched inflorescences of stalkless flowers): The one to three staminate, or male, spikes are located at the top, and the one or two pistillate, or female, spikes are lower on the culm. Pistillate spikes are stalkless or nearly stalkless, cylindric, and 2-4 cm (0.8-1.6 in) long. The uppermost staminate spike is 3-5 cm (1.2-2 in) long. Hairless, leathery-textured, 4.5-6.6 mm (0.18-0.26 in) long perigynia (sac-like structures that enclose the pistil) taper to a shallowly two-toothed beak. The pistillate scales, which subtend each of the female flowers, are red-purple on their sides. The lowest bract (modified leaf associated with a flower or inflorescence) reaches above the end of the culm. The achene (a type of dry, one-seeded fruit) is three-angled and widest at the middle. Mature fruits form in August.
Slender woolly-fruited sedge (Carex lasiocarpa) could easily be mistaken for Walter's sedge. However, slender woolly-fruited sedge has pubescent (hairy) perigynia; those of Walter’s sedge are hairless.
Life cycle and behavior
Walter’s sedge is a perennial sedge that often forms extensive colonies. Mature fruits form in August.
Population status
Walter's sedge is currently listed as Endangered in Massachusetts, where there are five current stations (discovered or relocated since 1984) in five towns and four historical stations (unverified since 1984). Walter's sedge is also considered rare in New York, New Hampshire, Rhode Island, Virginia, North Carolina, and Alabama. The MassWildlife’s Natural Heritage & Endangered Species Program database has 7 records from 2 counties: Barnstable and Plymouth. 4 of these records have been observed within the last 25 years.
Distribution and abundance
The documented range of Walter's sedge is the coastal plain from southeastern Massachusetts to northern Florida.
Distribution in Massachusetts
1999-2024
Based on records in the Natural Heritage Database
Habitat
In our area, Walter’s sedge prefers boggy pondshores and open peaty swamps. Specific habitats include the upper border of a sandy beach, a pondshore with peaty-muddy substrate, a shrub bog with a wet pool, a former shrub bog that has been partially cleared, and a peat bog in a cranberry reservoir. Among the plant species associated with Walter’s sedge are leatherleaf (Chamaedaphne calyculata), cranberry (Vaccinium macrocarpon), dwarf huckleberry (Gaylussacia dumosa), the sedge small-headed beak-rush (Rhynchospora capitellata), and various rushes (Juncus spp.). Rare Massachusetts plants that have been found with Walter's sedge include the following coastal plain pond species: inundated horned-sedge (Rhynchospora inundata), Plymouth gentian (Sabatia kennedyana), and terete arrowhead (Sagittaria teres).
Threats
Threats to the species include land development and crushing by both foot traffic and boats.
Contact
| Date published: | April 9, 2025 |
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