Rare Species Guide

  Synonyms

Carex annectens var. xanthocarpa, Carex brachyglossa

  Basis for Listing

The status of Carex annectens in Minnesota is difficult to determine from the available information. It appears to be a native inhabitant of prairies over a rather broad swath of southern Minnesota. We know that prior to settlement, prairies were the predominant feature on the landscape of that region, covering millions of acres. Yet for some reason, C. annectens went undetected in Minnesota until1978, by which time the pre settlement prairies had been reduced to scattered isolated remnants. This history might indicate that C. annectens was simply too rare to be picked up by the rather random and sporadic botanical work conducted during the early years of settlement. Certainly modern botanists have more resources at their disposal and tend to be more thorough in their plant surveys. Yet even modern botanical surveys of prairie remnants rarely encounter this species. Carex annectens was listed as a special concern species in Minnesota in 1984.

  Description

Carex annectens is a perennial sedge that grows to a height of about 80 cm (2.6 ft.). The stems have brown bases and arise from a relatively dense clump. The leaf blades have a maximum width of about 4 mm (0.16 in.), and the leaf sheaths are transversely wrinkled. The inflorescence is a continuous panicle up to 7 cm (2.8 in.) long, and it consists of numerous spikes crowded onto 10-15 short, compact branches. The spikes are alike in appearance, and have the female flowers above and the male flowers below. Carex annectens looks very similar to the common C. vulpinoidea (fox sedge), but the following combination of characters can be used to confirm C. annectens. The leaves are shorter than the stems; the perigynia are 1.9-2.5 mm (0.07-0.10 in.) long and have a length/width ratio of 1.5-1.9; and the beak of each perigynium is 0.5-0.9 mm (0.020-0.035 in.) long and constitutes 1/4-1/3 the length of the entire perigynium. Also, the perigynia lack veins on the dorsal surface, or they may have only a few discontinuous veins at the base. The body of the perigynium is generally widest below the middle, and only the lowest floral bract is longer than the spike it subtends.

  Habitat

In Minnesota, C. annectens is found in native meadows and prairies with soil moisture conditions that include mesic, dry-mesic, and somewhat wet. The wetter sites are usually located at the edge of a marsh or sedge meadow, where the species may be associated with Valeriana edulis var. ciliata (valerian), a threatened species, or C. pellita (woolly sedge). On the mesic or dry-mesic sites, C. annectens would be associated with typical prairie grasses such as Andropogon gerardii (big bluestem) and Sorghastrum nutans (Indian grass).

  Biology / Life History

There is very little published information about C. annectens. What little there is comes mostly from notes associated with herbarium collections and from taxonomic studies. Anything about its biology and life history must be inferred from secondary sources or from direct observation. The structure of C. annectens reveals it to be a deep-rooted perennial with little if any capacity to reproduce vegetatively. It produces flowers that are pollinated by wind, and small hard seeds (achenes) that are dispersed short distances by gravity or wind and perhaps longer distances by animals, probably birds and small mammals. Given the nature of prairie habitats in southern Minnesota, it is reasonable to assume that C. annectens is adapted to periodic wildfire, cyclical drought, and localized spring (dormant season) flooding. It appears to be a strong competitor, able to maintain a long-term presence in dense, stable vegetation. It does not, however, appear to be a dominant species in any community, except perhaps in small areas.

The best time to search for C. annectens is when the seeds are mature, from mid-June to early August.

  Conservation / Management

From all indications, if the habitat of C. annectens is maintained in a healthy, functional condition, then C. annectens will do fine. Very few, if any, species-specific management actions need to be considered. For the habitat, prescribed burns conducted in a dormant season on perhaps a 3-5 year rotation would be appropriate to reduce the accumulation of leaf-litter and control the encroachment of woody vegetation. Controlling exotic sod-forming grasses such as Bromus inermis (smooth brome) and Poa pratensis (Kentucky bluegrass) will be a greater challenge.

  Conservation Efforts in Minnesota

Carex annectens is known to occur in several areas managed by the Minnesota Department of Natural Resources including Beaver Creek, Cartney, Indian Lake, and Vale Wildlife Management Areas and Iron Horse Prairie, Mound Spring Prairie, Kellogg-Weaver Dunes, and Swedes Forest Scientific and Natural Areas.

  References and Additional Information

Smith, W. R. 2018. Sedges and rushes of Minnesota: the complete guide to species identification. University of Minnesota Press, Minneapolis. 696 pp.

Standley, L. A. 2002. Carex sect. Multiflorae. Pages 281-285 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 23. Oxford University Press, New York, New York.