1. Lepidium latifolium A.K.A. Dittander Dittany Broad-leaf Pepperweed Peppergrass Pepperwort Perennial Peppercress Perennial Pepperweed Tall Pepperweed Tall Whitetop Whitetop Ect., ect., ect.

2. Characteristics:  Perennial herb  Brassicaceae (Mustard Family)  Related to broccoli, beets, cabbage, canola, and other crops  Erect, up to 6 feet tall  Roots up to 10 feet long!  Distinguish rosettes from natives with long stemmed leaves (natives are sessile)

3. Native Range (uncommon)

4. North American Distribution (very common)

5. Where is it?  Native to SE Europe & SW Asia, uncommon  Arrived with beet seed from Europe before 1840  17 million acres in West  20,000 acres of the Truckee river  Primarily a riparian species  But, is now found in drier rangelands  Is it adapting more?

6. Why are they doing so well? Characteristics A.Extremely long straight taproots B.Can tolerate saturated soil for long periods C.Sprouts from root fragments (like a potato) D.Alters soil characteristics E.Tastes really BAD Competition Gets to the water table faster than natives Survives flooding Survives trampling Sucks up Ca+ salts and leaves it on top of soil Cattle and deer avoid it

7. How it is changing our landscape. Displacing native vegetation Bad forage Take up a lot of water Increasing stream incision Creates light impermeable layer of duff

8. How does it fit our 10 hypothesis? Competition hypothesis: Definitely! Takes over riparian areas Shades out neighbors Reaches water table better Escape from enemy constraints: Maybe… Biocontrols are under study Not sure if bugs are limiting Don’t care

9. How does it fit our 10 hypothesis? Variable Resource Availability: Ruderal species Grows tall fast High density + long root = lowers water table below what natives are used to Disturbance and Land use: Riparian areas frequently flood And frequently damaged by livestock

10. Approved Herbicides (you’re going to need a LOT) Telar® (chlorsulfuron) Noncrop Industrial Selective herbicide (will not harm most grasses), do not apply near water. Excellent control for 1- 2 years Habitat® (imazapyr) Stalker® (imazapyr) Riparian Wetland Wildlands Nonselective herbicide, do not apply near water Excellent control for 1- 2 years. Treated areas typically remain void of any vegetation for 1-2 years after treatment. Roundup® and others (glyphosate) Rodeo®, Aquamaster® and others (glyphosate) Wildlands Aquatic Nonselective herbicide. Rodeo® for areas near/in aquatic sites. Effective unless infestation is dense. If dense, mow area and apply to resprouting plants. Weedar 64® (2,4-D) Wildlands Aquatic Selective herbicide (will not harm grasses) Somewhat effective unless infestation is dense. If dense, mow area and apply to resprouting plants

11. Methods of Control and other Theories  Submerging for a very long time (2years?)  Mow and spray with white leaf rust (fungus)  Mite from Turkey  Leaf hopper from Elko  Stem boring maggots

12. Goats !! Can be trained to selectively eat perennial Pepperweed

13. Sources Cited: http://plants.usda.gov/java/profile?symbol=LELA2 http://www.unce.unr.edu/programs/sites/tallwhitetop/ http://www.fs.fed.us/database/feis/plants/forb/leplat/habitat.jpg http://www.nps.gov/plants/alien/fact/lela1.htm http://www.invasivespecies.net/database/species/ecology.asp?si=996&fr=1&sts=&lang=EN http://www.weedid.wisc.edu/idpics/sized_650/lepidium_latifolium4_650.jpg http://flora.nhm-wien.ac.at/Seiten-Arten/Lepidium-latifolium.htm Brain Rector, Elizabeth Leger, and of course….Robert Nowak & Erin Georgen