ILLINOIS PLANT INFORMATION NETWORK
 
 ILPIN INFORMATION ON    Carex retrorsa
 
 
 CLASS:    MONOCOTYLEDENAE
 ORDER:    CYPERALES
 FAMILY:   CYPERACEAE
 SCIENTIFIC NAME:  Carex retrorsa
 AUTHORITY:  Schwein.
 
 COMMON NAMES:
    KNOTSHEATH SEDGE
 
 SYNONOMY:   None
 
 PLANTS CODE: CARE4
 
 NATURAL COMMUNITIES:
     WETLAND
       MARSH
 
 
 SAF FOREST COVER TYPE:
     NO
 
 NATURAL DIVISION:  UNAVAILABLE
 
 COUNTIES:
   ADAMS           COOK            DUPAGE          FULTON          HENDERSON
   JASPER          KANE            LAKE            MCHENRY         SANGAMON
   UNION           WINNEBAGO
 
 GROWTH FORM:  Monocot
 
 TAXONOMIC CHARACTERISTICS:
    ROOTS:  Adventitious   (fibrous)   (rhizomes)
    LEAF ARRANGEMENT:   Alternate
    LEAF TYPE:   Simple
    LEAF MARGIN:   Entire
    LEAF VENATION:  Parallel
    LEAF SHAPE:     Linear
    INFLORESCENCE:   Spike
    FLOWER MEROUS:  3
    FLOWER STRUCTURE:   Incomplete  (no petals)  (no sepals)
    FLOWER PLACEMENT:  Hypogynous
    FRUIT:   Achene
 
 DISTINGUISHING CHARACTERISTIC COMMENTS:
     In large, loose tussocks, leaves and bracts greatly prolonged, lax,
     dark green, flat. Pistillate spikes ascending to spreading,
     mostly closely crowded; thick cylindric. Perigynia thin, papery,
     stramineous-brown, shiny, ovoid, with a prolonged, toothed beak.
     Perigynia coarsely nerved, highly inflated, much exceeding the
     scales. Achenes bluntly 3-angled, with an abruptly bent or
     twisted style.
 
 GEOGRAPHIC INFORMATION:
     ORIGIN:   Native
 
 GEOGRAPHIC COMMENTS:
     Species is scattered in Illinois.
 
 POPULATION DYNAMICS:
     STATE STATUS: Not listed
     FEDERAL STATUS: Not listed
     COMMONNESS:  Rare
     ENDEMIC:   NOT-ENDEMIC
 
 BIOLOGIC:
     HABIT:   Grasslike
     LIFE CYCLE:   Perennial
     REPRODUCTION:   Sexual   Vegetative
     FLOWERING PERIOD:
         MONTH BEGINNING-      7         MONTH END-     10
     TROPHIC STATUS:  Autotrophic
     SEX:      Unisexual   -monoecious
 
 BIOLOGIC COMMENTS:
     Upper 1-4 spikes are staminate; lower, smaller 3-8 spikes
     are pistillate.
 
 ECODISTRIBUTION COMMENTS:
     Species is distributed with Cornus obliqua (Typha latifolia).
 
 ENVIRONMENTAL RELATIONSHIPS:   No data entered
 
 FUNCTIONAL RELATIONSHIPS:
     MYCORRHIZAE:   no
 
 HUMAN RELATIONSHIP DATA:    No data entered
 
 WILDLIFE AND LIVESTOCK INFORMATION:   No data entered
 
 REVEGETATION PLANTINGS:
     WEEDINESS:   Non-weedy
 
 
 
 REFERENCES:
Mohlenbrock, R. H., ed.  1975.  Guide to the vascular flora of Illinois.
     Southern Illinois University Press, Carbondale.  494 pp.
Fernald, M. L.  1950.  Gray's manual of botany.  8th ed.  American Book Co.,
     New York.  1632 pp.
Swink, F., and G. S. Wilhelm.  1979.  Plants of the Chicago region.  Third ed.
     The Morton Arboretum, Lisle, Illinois.  922 pp.
Mackenzie, K. K.  1940.  North American Cariceae.  2 vols.  The New York
     Botanical Garden, New York.
 
 END OF DATA FOR SPECIES  Carex retrorsa
 
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 ILPIN was developed by Louis Iverson*, with data compiled by David Ketzner and Jeanne Karnes
 Illinois Natural History Survey, 607 E. Peabody Dr., Champaign, IL 61820
     *currently employed by USDA Forest Service, 359 Main Rd., Delaware, OH 43015