Carex crawei (Crawe's Sedge)
|Also known as:|
|Habitat:||sun; moist to wet sandy, gravelly or calcareous soil; fens, meadows, prairies, swales, ditches, limestome pavements|
|Fruiting season:||June - August|
|Plant height:||2 to 15 inches|
|Wetland Indicator Status:||GP: FACW MW: FACW NCNE: FACW|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Separate staminate (male) and pistillate (female) spikes, with a single staminate spike 3/8 to about 1 inch long at the top of the stem. Below the staminate spike are 2 to 4 cylindric, erect to ascending, all-pistillate spikes each 3/8 to about 1 inch long; the uppermost 1 or 2 are stalkless or short-stalked and well separated from the terminal spike by as much as 3 or 4 inches. Lower pistillate spikes are short stalked and arise singly from the nodes, the lowest spike on the lower half of the stem, often at the base. Pistillate spikes each have a long-sheathing, leaf-like bract at the base of the stalk, the blade longer than the spike but usually does not over-top the terminal spike.
Leaves and stems:
Leaves are basal and alternate on the lower stem, 1.5 to 4.4 mm wide, shorter than the flowering stem, erect to ascending and somewhat stiff. Stem leaf sheaths loosely wrap the stem. The ligule (membrane where the leaf joins the sheath) is longer or shorter than wide. Leaves are hairless, M-shaped in cross-section when young, sometimes folded, medium green to light green to yellowish green.
Bases are wrapped in a green to brown sheath that is not fibrous. Stems are slender, weakly 3-sided, smooth, mostly erect to ascending, some may elongate up to 15 inches at maturity. Stems are mostly single from the base, creating colonies from long rhizomes
Fruit develops in late spring through mid-summer, the pistillate spikes forming clusters of seeds (achenes), each wrapped in a casing (perigynium), subtended by a scale. Pistillate spikes are tightly packed with 10 to 45 fruits, the perigynia mostly ascending.
Pistillate scales are broadly egg-shaped to nearly triangular, brown with a green midrib, pointed at the tip or the midrib extending to a short awn, and much shorter than the perigynia. Perigynia are yellowish-green to pale brown at maturity, 2.2 to 3.5 mm long, 1.1 to 1.9 mm wide, many-veined, hairless, slightly inflated, may be resin dotted on the upper half, generally oval-elliptic, nearly round in cross-section, rounded at the base tapering to a short, straight, toothless beak. Achenes are 1.4 to 1.9 mm long, 3-sided, urn-shaped, brown at maturity.
Carex crawei is an occasional sedge of moist to wet, open areas including sedge meadows, prairies, fens and wet ditches, less often in wet woods or along shores or railroads. We encountered it in a wet prairie as well as an old gravel pit.
Carex is a large genus, with over 600 species in North America and 150+ in Minnesota alone. They are grouped into sections, the species in each group having common traits. Carex crawei is in the Granulares section; some of its common traits are: clump forming or not, short to long rhizomatous though may be inconspicuously so, basal sheaths not fibrous, leaves M-shaped in cross-section when young, leaves hairless, 3 to 6 spikes, terminal spike all staminate, lateral spikes all pistillate or with a few staminate flowers at the tip (androgynous), lateral spikes sometimes stalked, lowest spike subtended by a long-sheathing leaf-like bract, perigynia hairless, generally oval-elliptic, often dotted or streaked reddish or yellowish, distinctly veined and abruptly short-beaked, achenes 3-sided with 3 stigmas, growing in moist, open areas.
Carex crawei is one of the two members of the Granulares section in Minnesota, the other is Carex granularis. C. crawei is distinguished from other Carex species by the combination of: rhizomatous and not clump-forming, staminate spike usually well separated from the uppermost pistillate spike, lowest pistillate spike often at the base of the stem, perigynia many veined, often resin-dotted, and with a short, straight, toothless beak.
C. crawei resembles several other sedges, most notably members of the Griseae section, which have indented veins on mature perigynia where C. crawei veins are raised. It also resembles some members of the Laxiflorae and Paniceae sections, which have similarly shaped perigynia but their beaks more consistently bent where C. crawei is generally straight. C. crawei is most easily differentiated from C. granularis by having a pistillate spike at the base of the stem and the uppermost pistillate spike usually well-separated from the staminate spike, where C. granularis spikes are all in the upper stem and the uppermost 2 or 3 spikes are all crowded at the stem tip.
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- Carex crawei plant
- Carex crawei plant
- Carex crawei plants
- Carex crawei in an old gravel pit
- Carex crawei in a wet-mesic prairie
- more spikes
Photos by K. Chayka taken in Kittson County. Photos by Peter M. Dziuk taken in Brown and Kittson counties.
Have you seen this plant in Minnesota, or have any other comments about it?