Water Weeds: Guide to Aquatic Weeds in King County Department of Natural Resources and Parks Water and Land Resources Division Noxious Weed Control Program W W A A T T E E R ater eeds: R W W W W E uide to quatic eeds E E G A W E D D S in King County S • • A A Q Q U U A A T T I I C C W W E E E E D D S S I I N N On the cover: parrotfeather Inside cover: purple loosestrife, Department of K floating primrose-willow, Natural Resources and Parks K I Eurasian watermilfoil Water and Land Resources Division I N Page 2: native yellow pond-lily Noxious Weed Control Program N G (top and bottom) G Page 3: garden loosestrife 201 South Jackson, Suite 600 C Page 4: Brazilian elodea C O Page 5: Hydrilla Seattle, WA 98104-3855 O Page 6: purple loosestrife www.kingcounty.gov/weeds U Page 7: parrotfeather U N Page 8: yellow flag iris 206-296-0290 N T Page 9: common reed T Y Y W W A A T T E E R ContentsAquatic Noxious Weeds Included in This Guide R W W E E E EMERGENT FLOATING MAT E D 1. Common Reed 10 & 11 10. Floating Primrose-willow and Water Primrose 28 & 29 D S S (Phragmites australis) (Ludwigia peploides, L. hexapetala) • • 2. Cordgrasses 12 & 13 11. Parrotfeather 30 & 31 A (Spartina alterniflora, S. anglica, S. (Myriophyllum aquaticum) A Q densiflora, S. patens) Q U U A 3. Flowering Rush 14 & 15 FLOATING LEAF A T (Butomus umbellatus) T I 12. Fragrant Water Lily 32 & 33 I C 4. Garden Loosestrife 16 & 17 (Nymphaea odorata) C (Lysimachia vulgaris) W 13. Yellow Floating Heart 34 & 35 W Nymphoides peltata E 5. Grass-leaved Arrowhead 18 & 19 ( ) E E E D (Sagittaria graminea) D S S 6. Hairy Willowherb 20 & 21 SUBMERGED I (Epilobium hirsutum) 14. Brazilian Elodea 36 & 37 I N 7. Purple Loosestrife 22 & 23 (Egeria densa) N K (Lythrum salicaria) 15. Eurasian Watermilfoil 38 & 39 K I I 8. Reed Canarygrass (Myriophyllum spicatum) N 24 & 25 N G (Phalaris arundinacea) 16. Fanwort 40 & 41 G (Cabomba caroliniana) C 10. Yellow Flag Iris 26 & 27 C O (Iris pseudacorus) 17. Hydrilla 42 & 43 O U U To see the complete King County (Hydrilla verticillata) N N T noxious weed list, visit T Y www.kingcounty.gov/weeds Y W W A A T T E by natural controls such as herbivores, insects and E R What are R aquatic other plants. Native aquatic plants provide food W and habitat for fish, birds, and other wildlife. They W E plants? E E protect shorelines from erosion and often clean E D Plants that grow in pollution from the water. D S water are called aquatic S • plants. They grow in a What are aquatic • variety of forms. Emergent plants noxious weeds? A A are rooted in the soil and grow along shorelines, Q When aquatic plants are introduced to a new Q U floating plants grow in shallow to deep water and U area without the natural checks and balances A either have floating leaves or form floating mats on A T of their home waters, they can sometimes grow T I the surface of the water, and submersed plants grow I out of control, creating dense monocultures and C mostly under water. Many native aquatic plants grow C overwhelming lakes and streams. This guide W in Washington, and they are very beneficial to the describes some of these invasive, non-native aquatic W E environment and generally do not cause significant E E plants that have been introduced to Washington’s E problems. These native aquatic plants developed D water bodies (accidentally or as garden D S in the area naturally and usually are kept in check S plants). They are all highly aggressive I and create significant ecological I N N and economic damage when they K are not controlled. These invasive, K I I N non-native aquatic plants are N G called aquatic noxious weeds G C when they are identified by the C O Washington State Noxious Weed O U U N Board as having a significant N T negative impact on the state’s T Y natural and economic resources. Y 2 3 W W A A T T E closely resemble these weeds. If you find a plant that E R Impacts of R invasive looks like one of the weeds in this guide, we suggest W you consult the more detailed references listed at W E aquatic E E weeds: the back of this guide or ask an expert for help with E D getting a positive identification. D S . loss of native plant S communities • What can we do about • . disruption of fish and wildlife habitat aquatic noxious weeds? A A Q . damage to commercial and sport fishing veryone can help prevent new introductions by Q U E U cleaning boats, trailers and other equipment, by A . reduced recreational activities like boating and swimming A T never dumping aquariums into lakes and creeks, T I . clogged irrigation and drinking water structures I C and by not planting invasive aquatic plants. Also, C . decreased water quality. early detection of an invasive aquatic weed greatly W increases the opportunity for preventing damage. If W E E E What aquatic weeds are you find an aquatic noxious weed in a new area, it is E D important that the responsible agency or landowner D S included in this guide? S is alerted as soon as possible, while there is still his guide describes 17 aquatic noxious weeds I T a chance to stop its spread. Even when I N on the Washington State Noxious Weed List to look N invasive weeds are already widely out for in King County. The weeds are grouped K established in a water body, it is still K I by growth form: emergent, floating mat, floating I possible to reduce their impact and N leaves, and submersed. Many of the weeds in N G contain their spread. For instance, it G this guide are already widespread in King County, can help to remove seed heads before C but some of them have only been found in a few C O they mature or to contain the weed by O U locations or only in nearby counties. The guide does U controlling new satellite populations. N not include any native aquatic plants, some of which N T T Y Y 4 5 W W A A T T E applies equally to private and E R What should I do R if I find an aquatic public property. However, W this requirement does not W E noxious weed? E E include noxious weeds that E D Mark the location of the plant with a weighted are widespread in the state D S S buoy if it’s in the water, or a flagged stake if it’s on or the county, but only those • the shore, and carefully collect a specimen including weeds where the state weed board • stems, leaves and any flowers or seed pods. Place believes there is still an opportunity to eradicate A A Q the specimen in a sealed container with water and it from all or part of the state. The noxious weeds Q U store in a cool, dark place. Contact the King County are classified by distribution: Class A weeds are the U A Noxious Weed Program at 206-296-0290 to A T highest priority statewide because they are highly T I make arrangements for getting the specimen limited in distribution, Class B weeds have a split I C C identified. If this is not possible, contact the distribution and control is required only where they W weed program and we can help determine if a are not already widespread, and Class C weeds are W E site visit is needed to identify the plant. E E the most widespread and their control is typically not E D required, although recommended where possible. D S What does the State S Noxious Weed Law I How do I know which I N require when it N comes to aquatic weeds have to be K controlled? K I noxious weeds? I N The King County and Washington State noxious N ashington’s noxious weed law (RCW G W weed lists are available online at www.kingcounty. G 17.10) requires property owners to control C gov/weeds or by contacting the King County C and stop the spread of noxious weeds O Noxious Weed Control Program at 206-296-0290. O U on their property, including both aquatic U N In this guide, the weed classification and any control N and non-aquatic noxious weeds. The law T requirement is provided for each weed described. T Y Y 6 7 W W A A T T E E R How do I find What help does the R W out more county provide for W E about permit aquatic noxious weed E E requirements control? E D D S for aquatic S weed control? The King County Noxious Weed Program is • available to provide information and advice on • Since aquatic plants are by definition growing in identification and control methods for aquatic weeds A A Q an easily disturbed, sensitive environment, any work and to guide property owners through the complex Q U done to remove them is regulated by state or local permit regulations that exist when working in U A laws.