ILLINOIS PLANT INFORMATION NETWORK
 
 ILPIN INFORMATION ON    Ambrosia psilostachya
 
 
 CLASS:    DICOTYLEDENAE
 ORDER:    ASTERALES
 FAMILY:   ASTERACEAE
 SCIENTIFIC NAME:  Ambrosia psilostachya
 AUTHORITY:  DC.
 
 COMMON NAMES:
    WESTERN RAGWEED
 
 SYNONOMY:   None
 
 PLANTS CODE: AMPS
 
 NATURAL COMMUNITIES:
     PRAIRIE
     CULTURAL
       AGRICULTURAL FIELD
       SUCCESSIONAL FIELD
       DEVELOPED LAND
 
 
 SAF FOREST COVER TYPE:
     NO
 
 NATURAL DIVISION:  UNAVAILABLE
 
 COUNTIES:
   ADAMS           CARROLL         CASS            CHAMPAIGN       CLINTON
   COOK            DEKALB          DUPAGE          EFFINGHAM       GREENE
   GRUNDY          HENDERSON       HENRY           JO DAVIESS      KANE
   KANKAKEE        KENDALL         LAKE            LASALLE         LEE
   MCHENRY         MACOUPIN        MARSHALL        MASON           MENARD
   MERCER          MORGAN          OGLE            PEORIA          PIKE
   PUTNAM          ROCK ISLAND     ST. CLAIR       SCOTT           TAZEWELL
   WHITESIDE       WILL            WILLIAMSON      WINNEBAGO       WOODFORD
 
 
 GROWTH FORM:  Dicot-herb
 
 TAXONOMIC CHARACTERISTICS:
    ROOTS:  Adventitious   (fibrous)   (rhizomes)
    LEAF ARRANGEMENT:   Alternate     Opposite
    LEAF TYPE:   Simple
    LEAF MARGIN:   Lobed  (pinnately)
    LEAF VENATION:  Pinnate
    LEAF SHAPE:     Lanceolate
    INFLORESCENCE:   Raceme  Spike  Head
    FLOWER STRUCTURE:   Incomplete  (no sepals)
    FLOWER COLOR:   Yellow   Green
    FLOWER PLACEMENT:  Epigynous
    FRUIT:   Achene
 
 DISTINGUISHING CHARACTERISTIC COMMENTS:
     Similar in appearance to Ambrosia artemisiifolia, but with a creeping rhizome,
     and thicker, short-petrolate to such sessile leaves.
 
 GEOGRAPHIC INFORMATION:
     ORIGIN:   Introduced-  N. America
 
 GEOGRAPHIC COMMENTS:
     Probably an early and unagressive introduction from west of Illinois, though may
     be native.
 
 POPULATION DYNAMICS:
     STATE STATUS: Not listed
     FEDERAL STATUS: Not listed
     COMMONNESS:  Occasional
     ENDEMIC:   NOT-ENDEMIC
 
 BIOLOGIC:
     HABIT:   Forb
     LIFE CYCLE:   Perennial
     REPRODUCTION:   Vegetative
     FLOWERING PERIOD:
         MONTH BEGINNING-      7         MONTH END-     10
     TROPHIC STATUS:  Autotrophic
     SEX:      Unisexual   -monoecious
 
 ECODISTRIBUTION COMMENTS:
     Along railroads, in weedy habitats; disturbed sandy soils; old cemeteries, waste
     ground.
 
 ENVIRONMENTAL RELATIONSHIPS:
     DISTURBANCE INDICATOR:   No
     SOIL CHEMISTRY INDICATOR:   None
     GROWTH OF SPECIES IN VARIOUS CONDITIONS:
          GRAVEL         No data entered    SAND           No data entered
          SANDY LOAM     No data entered    LOAM           No data entered
          CLAY LOAM      No data entered    CLAY           No data entered
          DENSE CLAY     No data entered    ORGANIC SOIL   No data entered
          NEUTRAL pH     No data entered    ACIDIC SOIL    No data entered
          EXTREMELY ACID No data entered    SALINE SOIL    No data entered
          SODIC SOIL     No data entered    SODIC-SALINE   No data entered
          ROCKY OUTCROPS No data entered    GENTLE SLOPES  Good
          MODERATE SLOPE Fair               STEEP SLOPES   Poor
     HABITAT:   Dry
 
 FUNCTIONAL RELATIONSHIPS:
     MAJOR POLLINATION AGENT:   Wind
 
 HUMAN RELATIONSHIP DATA:
     ALLERGENIC:  Maybe
 
 
 HUMAN FACTOR COMMENTS:
     Wodo house says all these Ambrosia species probably are allergenic.
 
 WILDLIFE AND LIVESTOCK INFORMATION:
     FOOD VALUE:  No data entered
     COVER VALUE:  No data entered
 
 LIVESTOCK PALATABILITY DATA:
     CATTLE FORAGE: No data    SHEEP FORAGE:  No data    HORSE FORAGE:  No data
     GOAT FORAGE:   No data    ENERGY VALUE:  Medium     PROTEIN VALUE: Low
     POISONOUS (LIVESTOCK):   No
 
 REVEGETATION PLANTINGS:
     WEEDINESS:   Economic
 
 
 
 REFERENCES:
Mohlenbrock, R. H., ed.  1975.  Guide to the vascular flora of Illinois.
     Southern Illinois University Press, Carbondale.  494 pp.
Swink, F., and G. S. Wilhelm.  1979.  Plants of the Chicago region.  Third ed.
     The Morton Arboretum, Lisle, Illinois.  922 pp.
Agricultural Experiment Station.  1981.  Weeds of the North Central States.
     Bulletin 772.  College of Agriculture, University of Illinois at Urbana-
     Champaign, Urbana.  303 pp.
Gleason, H. A.  1952.  The new Britton and Brown illustrated flora of the
     northeastern United States and adjacent Canada.  3 vols.  The New York
     Botanical Garden, New York.
Wodehouse, R. P.  1971.  Hayfever plants.  Hafner Publishing Company, New
     York.  280 pp.
 
 END OF DATA FOR SPECIES  Ambrosia psilostachya
 
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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