Presentation on the invasive Japanese chaff flower.

1. JAPANESE CHAFF
FLOWER (ACHYRANTHES
JAPONICA)
Chris Evans
River to River CWMA
www.rtrcwma.org

2. BACKGROUND
 Perennial Forb
 Up to 5-6 feet in height
 Young plants single
stemmed, older plants have
multiple stems
 First located in 1981 in
eastern KY and
southwestern WV
 Rapid spread throughout
the Ohio River Valley and
other regions
 Form extensive infestations
along riverine systems
2012 Invasive Species Workshop – St. Louis, MO

3. IDENTIFICATION
 Leaves opposite, entire, smooth edged
 Smooth to lightly pubescent
 Petioles vary in length, sometimes very long,
sometime near sessile
2012 Invasive Species Workshop – St. Louis, MO

4. IDENTIFICATION
2012 Invasive Species Workshop – St. Louis, MO

5. 2012 Invasive Species Workshop – St. Louis, MO

6. IDENTIFICATION
 Flowers occur in terminal spikes, diverge at right
angles
 Start very compact and elongate as the progress
 Lack petals
 Brush like, dull green
2012 Invasive Species Workshop – St. Louis, MO

7. IDENTIFICATION
2012 Invasive Species Workshop – St. Louis, MO

8. IDENTIFICATION
2012 Invasive Species Workshop – St. Louis, MO

9. IDENTIFICATION
 Terminal spike continues to elongate as flowers
mature into fruits
 Fruits deflex along the stem
 2 stiff bracteoles on each fruit
 Remain on dead stalk throughout winter
 Easily attached to clothing, fur, etc.
2012 Invasive Species Workshop – St. Louis, MO

10. IDENTIFICATION
2012 Invasive Species Workshop – St. Louis, MO

11. IDENTIFICATION
2012 Invasive Species Workshop – St. Louis, MO

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14. 2012 Invasive Species Workshop – St. Louis, MO

15. IDENTIFICATION
 Dense stands
 Flower or fruit spikes very noticeable
2012 Invasive Species Workshop – St. Louis, MO

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18. 2012 Invasive Species Workshop – St. Louis, MO

19. TIMING
 Initiates growing in late spring
 ‘Comes on’ in mid-late summer
 Flowering late summer
 Rapid seed set (late summer – early fall)
 Seed maturation – early fall
 Plant senescence – late fall
2012 Invasive Species Workshop – St. Louis, MO

20. SPREAD
 Water
 Animals
 Humans
 Produces thousands of seeds per plant per year
 Appear to be very viable based upon initial
attempts to grow in greenhouse
2012 Invasive Species Workshop – St. Louis, MO

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22. 2012 Invasive Species Workshop – St. Louis, MO

23. CURRENT DISTRIBUTION
2012 Invasive Species Workshop – St. Louis, MO

24. HABITAT
 Does best in moist, rich soils in partial shade –
full sun
 Sandy to loamy to silty soils
 Does not tolerate annual flooding or long periods
of inundation
 On big river systems, often found just above the
driftwood line
 Can grow in deep shade
2012 Invasive Species Workshop – St. Louis, MO

25. HABITAT
 Riparian areas
 Bottomland forests
 Roadsides
 Ditches
 Old fields
 Waste areas
2012 Invasive Species Workshop – St. Louis, MO

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29. IMPACTS
 Forms very dense thickets
 Near monoculture
 Seems to exclude many other species
 Even displacing stiltgrass
 Preferred forage for deer
 Lots of evidence for insect feeding
2012 Invasive Species Workshop – St. Louis, MO

30. 2012 Invasive Species Workshop – St. Louis, MO

31. MANAGEMENT
 Early Detection Rapid Response
 Monitoring and controlling this species in new
areas
 Spread prevention techniques and adoption of
BMPs in areas where this species is present
 Further education about this species
*Very few people currently know about this
plant or know to look for it*
2012 Invasive Species Workshop – St. Louis, MO

32. MANAGEMENT
 Spread prevention
 Clothing cleaning
 Equipment sanitation
 Targeted surveys in and around hiking areas and
campgrounds
 High use areas
2012 Invasive Species Workshop – St. Louis, MO

33. MANAGEMENT
 Research on control efforts underway
 Foliar sprays before flowering(mid summer)
 2% Glyphosate
 2% Triclopyr
 Large roots and brittle stems seem to limit hand
pulling
2012 Invasive Species Workshop – St. Louis, MO

34. SUMMARY
 This new species has rapidly spread throughout the
Lower Ohio River Valley and into other portions of
the SE and has recently been found in Missouri
 It is spread by flood waters and by humans and
animals
 It can form dense stands that appear to potentially
heavily impact riparian areas and bottomlands
 Spread prevention and EDRR should be implemented
 Control with foliar sprays of glyphosate or tricopyr
seem to be effective
 Much more research is being started on this plant
2012 Invasive Species Workshop – St. Louis, MO