Carex garberi Fern.
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Carex garberi ssp. bifaria, Carex garberi var. bifaria
Basis for Listing
When Carex garberi was first proposed as endangered in Minnesota in 1984, it was known in the state by a single herbarium specimen. That specimen was collected in 1947 in St. Louis County about 48 km (30 mi.) north of Duluth by the botanist, Olga Lakela. Her specimen was initially identified as the similar C. aurea (golden-fruited sedge) and her label described the habitat as a swampy area on Highway 53. Several years later, Lakela's specimen was correctly determined to be C. garberi. Because that particular site had never been relocated, it was unclear if the species still survived in the state. In 1992, it was found in Kittson County in an extensive, open, sedge fen complex. This discovery confirmed that its occurrence in the state was not a fluke.
Carex garberi is a perennial sedge. It produces shoots from a short rhizome. Several shoots may be clustered fairly close together giving a more or less clumped appearance. Leaves and flowering culms may reach approximately 20-30 cm (8-12 in.) in height. Leaves are a few millimeters wide and culms are about 1 mm (0.04 in.) wide. There are several spikelets (flowering heads) on each culm; the terminal spikelet usually has several to many female flowers at the top (producing perigynia or fruits) and male flowers (stamens) are on the lower portion. Rarely, some culms have only a few perigynia at the top of the terminal spikelet. These specimens can be confused with C. aurea if they are collected after the perigynia of C. aurea lose their distinctive golden-yellow or golden-orange color. Perigynia of C. garberi are white and have a granular appearance with magnification. It is important to note the fresh color of mature specimens in the field and to carefully examine the population for the typical form of the terminal spikelet (Voss 1972; Brumback 2001).
Because of the very few records of C. garberi in Minnesota, it is not entirely clear which habitats are preferred. The Kittson County wetland site is an extensive rich fen complex in an area dominated by C. lasiocarpa ssp. americana (fen wiregrass sedge) and C. buxbaumii (Buxbaum's sedge). Associated plants included Calamagrostis spp. (reedgrass species) and Cladium mariscoides (twig rush) on a peat mat about 0.5 m (20 in.) thick. Within this rich fen complex, C. garberi was localized in patches of sparser vegetation where the surface was encrusted with whitish deposits of calcium carbonate. The population in St. Louis County was observed in a small mat of herbaceous vegetation growing in a moist spot on rocks along the shore of Lake Superior.
Biology / Life History
Carex garberi produces leafy shoots in the spring from belowground rhizomes; fertile culms arise in June. This species has developed adaptations for wind pollination. Fertilized female flowers produce mature fruit rapidly in June and July. It is important for positive identification to locate the plants when the fruits are mature (in the genus Carex, the specialized sac containing the fruit or achene is referred to as a perigynium; pl. perigynia). From mid-July to August, the plants may drop their perigynia and in some years, or under some conditions, it may be difficult to find perigynia by mid-July.
Conservation / Management
Because C. garberi occurs in only two known locations in Minnesota, its continued presence in the state may hinge on protection of these sites. The rich fen complex in Kittson County occurs on a state Wildlife Management Area and is protected from commercial or agricultural development. But the wetland is not immune to hydrologic alterations related to agricultural activities, road and ditch maintenance, or wildlife management. A commitment to maintaining the hydrologic regime of this wetland is critical. The Lake Superior site is on private property with no protection at this time. This site faces the same threats affecting other attractive, rocky coastal areas, even if they are not developed. People are drawn to these attractive sites and they often alter them for various reasons to enhance their comfort, view, or recreation.
Conservation Efforts in Minnesota
The Lake Superior shoreline habitats were searched very carefully from 2000 through 2002 as part of the Minnesota DNR County Biological Survey; only small portions where access has not been possible remain to be searched. Botanists have been surprised and disappointed not to locate more populations, especially after the St. Louis County shoreline discovery. The Kittson County site is on land that is protected from development, although the management needs of C. garberi have not been specifically addressed.
Ball, P. W., and A. A. Reznicek. 2002. Carex. Pages 254-572 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 23. Oxford University Press, New York.
Brumback, W. E. 2001. Conservation and research plan: Carex garberi Fern. (Garber's Sedge or Elk Sedge) and Triantha glutinosa (Michx.) Baker (Sticky False Asphodel). New England Wild Flower Society, New England Plant Conservation Program, Framingham, Massachusetts. ii + 43 pp.
Voss E. G., 1972. Michigan Flora: Part I Gymnosperms and Monocots. Cranbrook Institute of Science Book 55, Bloomfield Hills, Michigan. 488 pp.