- Scientific name: Carex castanea
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
- Endangered (MA Endangered Species Act)
Description
Chestnut-colored sedge, a member of the sedge family (Cyperaceae), is a perennial, herbaceous, grass-like plant of calcareous seeps, fens, and wet meadows. Typically forming loose clusters of stems, the plant reaches a height of 30-90 cm (11-35 in) tall and is purple-tinged at its base.
To identify chestnut-colored sedge and other members of the genus Carex, a technical manual should be consulted. Species in this genus have tiny, wind-pollinated flowers that are borne in spikes. Each flower is unisexual and is closely subtended by small scales that largely conceal the flowers. The staminate (i.e., pollen-bearing) flowers are subtended by a single scale. The pistillate (i.e., ovule-bearing) flowers are subtended by two scales, an outer flat scale (pistillate scale) and an inner, sac-like scale, called a “perigynium,” that encloses the flower, and later, the achene (a small, hard seed-like fruit). If the perigynium tapers or contracts to a tip, it is described as a “beak.”
The fruiting stems of the chestnut-colored sedge are longer than the leaves, which are 3-6 mm (0.1-0.2 in) wide and softly pubescent (hairy). The uppermost spike is staminate. The lateral, pistillate spikes are narrowly cylindric and droop from long, slender stalks (peduncles). The pistillate scales, for which the plant is named, are tinged with a chestnut-brown color. The perigynia are red-dotted, lance-shaped, and smooth with two prominent ribs and several fine veins. The perigynia taper to a short, minutely two-toothed beak that is half as long as the body. Achenes are three-sided with concave sides.
In Massachusetts, the chestnut-colored sedge is quite distinct in having the following combination of features: hairy leaves, drooping pistillate spikes, and entirely staminate terminal spikes. Other rare sedges of calcareous areas that may be confused with the chestnut–colored sedge are Davis’ sedge (C.davisii; Endangered) and the handsome sedge (C. formosa; Threatened), which also have drooping pistillate spikes, pubescent leaves, and red-dotted perigynia. However, in these two sedges, the terminal spike bears both staminate flowers (usually evident as empty-looking scales at the base of the spike) and pistillate flowers.
Population status
Chestnut-colored sedge is listed under the Massachusetts Endangered Species Act as Endangered. All listed species are protected from killing, collecting, possessing, or sale and from activities that would destroy habitat and thus directly or indirectly cause mortality or disrupt critical behaviors. Chestnut-colored sedge was first discovered in Massachusetts in 1984. The nine known stations are all in Berkshire County. Massachusetts is at the southern extent of chestnut-colored sedge's range. The sedge is believed to be rare in the state because it prefers cooler northern climates and calcareous soils that are not plentiful in the Commonwealth. The Massachusetts Natural Heritage & Endangered Species Program database has 10 records from 1 county: Berkshire. Nine of these records have been observed within the last 25 years.
Distribution and abundance
The documented range of chestnut-colored sedge extends from Newfoundland west to Manitoba, south to Connecticut, and west to Michigan and Minnesota. It is disjunct from the rest of its range in Tennessee.
Distribution in Massachusetts
1999-2024
Based on records in the Natural Heritage Database
Habitat
Chestnut-colored sedge is found in calcareous seeps within wet meadows, deciduous or mixed forests, and along river and pond shores. It is capable of tolerating disturbance and is often found in transitional habitats, such as in forest edges next to open land. The known occurrences in Massachusetts are in a seepage marsh at the edge of an artificial pond and in open, calcareous wet meadows. Typically associated with this species are other sedges, including marsh-sedge (C. lacustris), panicled sedge (C. diandra), inland prickly sedge (C. interior), porcupine sedge (C. hystericina), awl-fruited sedge (C. stipata), and yellow sedge (C. flava). Other associates include willows, such as autumn willow (Salix serissima), hoary willow (S. candida), and long-beaked willow (S. bebbiana). Other species documented to occur with chestnut-colored sedge in Massachusetts include sugar maple (Acer saccharum), old field cinquefoil (Potentilla simplex), steeple-bush (Spiraea tomentosa), sensitive fern (Onoclea sensibilis), and marsh fern (Thelypteris palustris).
Healthy habitats are vital for supporting native wildlife and plants. Explore habitats and learn about conservation and restoration in Massachusetts.
Conservation
As for many rare species, exact needs for management of chestnut-colored sedge are not known. The following comments are based primarily on observations of the population in Massachusetts. The Massachusetts populations are found growing in full light. Hand-clearing of woody vegetation that creates shade may be necessary to maintain the populations. In particular, woody non-native species, such as shrubby honeysuckles (Lonicera spp.) and buckthorns (Rhamnus spp.), should be removed due to their aggressive growth and potential for shading.
Contact
| Date published: | April 9, 2025 |
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