Sedges differ from grasses by having a 3-angled stem and structurally different flowers where the female flowers are enclosed in a sac like structure called the perigynium, which is subtended by a single scale. Longstalk Sedge is a smaller perennial loosely tufted sedge of woodlands and is widely distributed in the northern forests. The flowering stems (culms) grow only 3.5 to 11 inches high that are acutely 3-angled and often droop when mature.
The basal leaf sheaths are strongly reddish to purple with blades no longer than 1 cm on non-flowering stems; less strongly colored on flowering stems.
The leaf blades are mostly basal, dark green, only 1.4 to 4 mm wide and usually exceed the stem in length. In cross section, the blade is thick, margins may be smooth or rough. The blades over-winter, remaining green and then the tips of those blades frequently die off early showing an abrupt division between the live and dead parts.
The inflorescence consists of stalked flowering spikes with usually only a single terminal erect staminate (male) flower spike, 7.5 to 9.8 mm long by 1.8 to 2.3 mm wide, and below it on the flowering stem, 2 to 5 pistillate (female) flower spikes that rise from basal nodes on the stem with the lower spikes drooping on long slender stalks (up to 13 cm long) and the upper female spikes ascending on shorter stalks. Both types of spike tend to have a few flowers of the opposite sex - the female spikes with some male flowers at the top and the male spike with a 2 to 5 female flowers at its base. There are bracts at the base of the lower spikes which have short sheaths.
The perigynia, (The bladder-like sacs that enclose the female flower and later the fruit are called perigynia, singular - perigynium) are ovoid in shape, 3.7 to 6 mm long and 1.4 to 1.7 mm wide, with a tapering base that becomes stalk-like when dry. This base is an oil body (an elaiosome) that attracts ants which then help disperse the seeding body. The tip of the perigynia is pyramidal in shape and forms an abrupt tiny beak that is usually bent. The scales of the female spikes are dark brown to reddish-brown, ovate in shape, with tips that vary from obtuse to notched to abruptly pointed; they have a midvein that extends to form a short awn. There are 3 stigmas to the flower, usually some fine hair on the perigynia.
Seed: Mature fruit is an ellipsoid shaped achene 2.5 × 1.5–1.6 mm. The achene is subtended by an elaiosome, an oily appendage that attracts ants and helps with the dispersal of the seed. Florets are wind pollinated. Carex achenes usually require 60 days of cold stratification for germination - or sown outside in the Fall.
Habitat: Longstalk Sedge grows in woodland openings with a root system that is stout-rhizomatous. It grows in partial shade to dappled sun, usually in rich soils, with moderate moisture. It is one of the early blooming woodland sedges. It is an early colonizer and is later replaced by more robust species. The leaves and height resemble grass.
Names: The genus name, Carex, is from the Latin, being the old name for Sedges. The species, pedunculata, means 'with a defined stalk' and refers to the stalked spikes of this species. The author names for the plant classifications are as follows: First to publish was ‘Muhl’ which refers to Gotthilf Heinrich Ernst Muhlenberg (1753-1815) American Botanist who produced several catalogues of plants after retiring as a Lutheran pastor. His work was recognized but added to by ‘Willd.’ which refers to Carl Ludwig Willdenow (1765-1812), German botanist, a founder of the study of the geographic distribution of plants. He was director and curator of the Botanic Garden of Berlin.
Comparisons: Longstalk Sedge is a member of the sedge section Clandestinae where the species have rhizomatous root systems, red-purple bases to the stems, membranous sheath fronts, racemose shape inflorescences with 2 to 6 spikes, the terminal spike staminate or androgynous, lower pistillate scales dark brown to black, perigynia erect to ascending with a tapering base and an abrupt beak; 3 to 4 stigmas. Longstalk Sedge is the easiest of the group to distinguish from others by having most pistillate spikes emerge from basal nodes on long stalks, up to 13 cm long, the perigynia 3.7 to 6 mm long, and the leaves dark green, equaling or exceeding the length of the stems and after flowering by the die back on the leaf blade tips.
Above: The staminate florets are at the top of the spike with the pistillate florets below on the long stem rising from basal nodes. Drawing of Long-stalk Sedge from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York.
Below: The upper staminate florets, below the pistillate florets (both together in 2nd and 3rd photos). Note the dried blade tip - characteristic of this species.
Below: 1st photo - the terminal staminate spike. 2nd and 3rd photos - The basal sheaths with their short blades.
Longstalk Sedge is one of over 150 sedges native to Minnesota. It is fairy common in Minnesota with only 20 counties not reporting it and most of those are in the western side of the state. In North America it is found in the Dakotas, Minnesota and Iowa, then every other state east of the Mississippi exc. Mississippi and Florida in the U.S. and in Canada it is known across the lower provinces except Labrador. It is a member of the Clandestinae sect. of sedges.
Longstalk Sedge was planted in the Garden in 1987 by Gardener Cary George.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"