ILLINOIS PLANT INFORMATION NETWORK
 
 ILPIN INFORMATION ON    Poa annua
 
 
 CLASS:    MONOCOTYLEDENAE
 ORDER:    CYPERALES
 FAMILY:   POACEAE
 SCIENTIFIC NAME:  Poa annua
 AUTHORITY:  L.
 
 COMMON NAMES:
    ANNUAL BLUEGRASS
    LOW SPEARGRASS
    SIX-WEEKS GRASS
 
 SYNONOMY:   None
 
 PLANTS CODE: POAN
 
 NATURAL COMMUNITIES:
     FOREST
     PRAIRIE
       TYPICAL PRAIRIE
         DRY
         DRY-MESIC
         MESIC
     WETLAND
       BORDER OF LAKE
     CULTURAL
       AGRICULTURAL FIELD
         PASTURELAND
       SUCCESSIONAL FIELD
       DEVELOPED LAND
 
 SAF FOREST COVER TYPE:  UNAVAILABLE
 
 NATURAL DIVISION:  UNAVAILABLE
 
 COUNTIES:
   ADAMS           ALEXANDER       BOONE           BUREAU          CALHOUN
   CARROLL         CASS            CHAMPAIGN       CHRISTIAN       CLARK
   CLAY            CLINTON         COLES           COOK            CRAWFORD
   CUMBERLAND      DEKALB          DEWITT          DOUGLAS         DUPAGE
   EDWARDS         FAYETTE         FRANKLIN        FULTON          GALLATIN
   GREENE          GRUNDY          HANCOCK         HARDIN          HENRY
   IROQUOIS        JACKSON         JEFFERSON       JERSEY          JO DAVIESS
   JOHNSON         KANE            KANKAKEE        KENDALL         KNOX
   LAKE            LAWRENCE        LIVINGSTON      MCDONOUGH       MCHENRY
   MACON           MACOUPIN        MADISON         MARION          MASON
   MASSAC          MENARD          MERCER          MONROE          MORGAN
   MOULTRIE        PEORIA          PERRY           PIATT           PIKE
   POPE            PULASKI         RANDOLPH        RICHLAND        ST. CLAIR
   SALINE          SANGAMON        SHELBY          UNION           VERMILION
   WABASH          WASHINGTON      WHITE           WHITESIDE       WILL
   WILLIAMSON      WINNEBAGO
 
 GROWTH FORM:  Monocot
 
 TAXONOMY COMMENTS:
     Steyermark (ref. 4) discusses two aquatic varieties submerged
     partially or completely in cold springs -- appear very different
     from the common annua, which is described above.
 
 TAXONOMIC CHARACTERISTICS:
    ROOTS:  Adventitious   (fibrous)
    LEAF ARRANGEMENT:   Alternate
    LEAF TYPE:   Simple
    LEAF MARGIN:   Entire
    LEAF VENATION:  Parallel
    LEAF SHAPE:     Linear
    INFLORESCENCE:   Panicle
    FLOWER MEROUS:  3
    FLOWER STRUCTURE:   Complete
    FLOWER PLACEMENT:  Hypogynous
    FRUIT:   Grain
 
 DISTINGUISHING CHARACTERISTIC COMMENTS:
     Versus other Illinois Poa, this species lacks a web at the
     base of the lemma.
 
 GEOGRAPHIC INFORMATION:
     ORIGIN:   Introduced-  Europe   Asia
 
 GEOGRAPHIC COMMENTS:
     Species is probably found in every county.
 
 POPULATION DYNAMICS:
     STATE STATUS: Not listed
     FEDERAL STATUS: Not listed
     COMMONNESS:  Common
     ENDEMIC:   NOT-ENDEMIC
 
 BIOLOGIC:
     HABIT:   Grasslike
     LIFE CYCLE:   Annual
     REPRODUCTION:   Sexual
     FLOWERING PERIOD:
         MONTH BEGINNING-      4         MONTH END-     11
     TROPHIC STATUS:  Autotrophic
     C02 FIXATION:  C3
     SEX:      Perfect
 
 ECODISTRIBUTION COMMENTS:
     Species is distributed on waste ground, gardens, lawns, fields, along paths and
     disturbed woodland.
 
 ENVIRONMENTAL RELATIONSHIPS:   No data entered
 
 FUNCTIONAL RELATIONSHIPS:
     MYCORRHIZAE:   endomycorrhizal
 
 HUMAN RELATIONSHIP DATA:
     ALLERGENIC:  Yes
 
 
 WILDLIFE AND LIVESTOCK INFORMATION:   No data entered
 
 REVEGETATION PLANTINGS:
     WEEDINESS:   Economic
 
 
 
 REFERENCES:
Swink, F., and G. S. Wilhelm.  1979.  Plants of the Chicago region.  Third ed.
     The Morton Arboretum, Lisle, Illinois.  922 pp.
Mohlenbrock, R. H.  1967-continuing.  The illustrated flora of Illinois.
     Southern Illinois University Press, Carbondale.
Agricultural Experiment Station.  1981.  Weeds of the North Central States.
     Bulletin 772.  College of Agriculture, University of Illinois at Urbana-
     Champaign, Urbana.  303 pp.
Downton, W. J. S.  1975.  The occurrence of C4 photosynthesis among plants.
     Photosynthetica 9(1): 96-105.
 
 END OF DATA FOR SPECIES  Poa annua
 
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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