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Invasive Weeds on the Middle Fork Snoqualmie. Sasha Shaw Education Specialist King County Noxious Weed Program. Agenda. Weed Definitions Middle Fork Weed Priorities Priority Weeds Present in the Watershed Class A and B Noxious Weeds Other Priority Invasive Weeds
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Invasive Weeds on the Middle Fork Snoqualmie Sasha Shaw Education Specialist King County Noxious Weed Program
Agenda • Weed Definitions • Middle Fork Weed Priorities • Priority Weeds Present in the Watershed • Class A and B Noxious Weeds • Other Priority Invasive Weeds • Other Widespread Weeds and Lower Priority Plants Present but not Surveyed • Noxious Weeds Threatening to Invade
What is an Invasive Weed? • Introduced / non-native • Ability to out-compete native plants • Lack of predators or natural controls • Ability to modify local ecology • Aggressive ability to reproduce Invasive knotweed is one of the toughest plants to control and damages some of the highest quality habitats
What is a Noxious Weed? • Non-native plant that impacts agriculture, wildlife, human health, land values or natural resources • Defined and regulated by state law (RCW 17.10) • county lists are chosen from the state list • regulated in parts of the state where they have limited distribution
What are the Weed Classes? • Class A Weeds – new invaders, control required statewide, still a chance to eradicate • Class B and C Designates – control required in King County, still have a chance to stop them from getting established • Non-Designates and Weeds of Concern – widespread invasive weeds in King County, control not required but definitely a good idea whenever possible!
Middle Fork Snoqualmie Weed Priorities • King County Noxious Weeds • Class A’s, B-designates, and C-selects • Non-designates and Weeds of Concern that are limited in distribution and still controllable • Non-native species newly introduced or not previously reported in the valley • Excluded from the survey: species that are already pervasive in the valley and unlikely to be controlled valley-wide
Middle Fork Snoqualmie Weed Surveys Completed 2005 and 2006 • Roadsides (10 ft in on both sides) • Farther in where disturbance or weed infestations were observed • Disturbed Sites • Quarries, cut banks, logging landings • Camping sites, pullouts, trailheads, parking lots • Open talus fields, stream crossings • River by raft and river bars on foot
Himalayan and Evergreen Blackberry Bohemian Knotweed Scotch Broom Reed Canary Grass English Holly English Ivy Butterfly Bush Tansy Ragwort* Yellow Hawkweed* Canada Thistle Hedge Bindweed Common Tansy Yellow Archangel Yellow Flag Iris European Mountain-Ash Spotted Knapweed* Bittersweet Nightshade Poison-hemlock Priority Weeds Identified in the Middle Fork Valley Listed in order of total area found. Weeds with * are designated for control in King County.
Class A and B Noxious Weeds (Please notify the county noxious weed program if these are found)
Class B Noxious Weed Tansy Ragwort (Senecio jacobaea) Flowering stems are 1-6 ft tall with clusters of yellow, daisy flowers First year rosettes have round-lobed leaves, reddish stems Flowers June to October. Seeds are viable for 10 to 16 years.
Yellow Hawkweed(Hieracium caespitosum) Flowers: Yellow, in tight clusters Leaves: Hairy on top and bottom, glandular and stellate hairs Roots: stoloniferous, rhizomatous
Non-native Hawkweeds • Stiff hairs on stems, leaves • Basal rosette of spatula shaped leaves • Small flowers, often in tight clusters near tops of stems • Flower buds and bracts covered with black hairs • Stolons Black hairs on flower buds
Yellow Hawkweed(Hieracium caespitosum) • Rosettes: March-April • Bolting: April-early June • Flowers: May-July • Seeding: July to September
Grows 3 - 5 feet tall, perennial Pink to purple flowers, on the tips of stem branches Floral bracts tipped with dark fringe Bolting: April to July Flowering: May to October Seeding: August to October Spotted Knapweed (Centaurea stoebe)
Evergreen Blackberry(Rubus laciniatus) http://www.nic.funet.fi http://www.biopix.dk
Good Guy Look-Alike:Native Trailing Blackberry (Rubus ursinus)
Hollow, upright, bamboo like stems often reddish or red-speckled
Giant Knotweed(Polygonum sachalinense) Large leaves give giant knotweed its common name elephant ear bamboo Giant knotweed in early spring with last year’s dead stems
Knotweed Invasion on Rivers Knotweed rapidly spreads along rivers as fragments get moved by floods and grow into new clones downriver
Butterfly Bush (Buddleia davidii) Leaves gray green above and white and fuzzy on the underside, finely toothed on margins Can grow 5 to 8 feet in a single season
Butterfly Bush (Buddleia davidii) Seedlings thrive in open sandy soil Butterfly bush has invaded along the Tolt River
Common Tansy (Tanacetum vulgare) Button-like flowers are clustered at top of plant Leaves are fern-like with sharply toothed edges and a strong odor
Bittersweet Nightshade (Solanum dulcamara) http://oregonstate.edu/dept/nursery-weeds
University of Wisconsin Canada Thistle (Cirsium arvense) Spreads underground to form dense infestations in sunny fields Spreads by seed to new sites
Native Thistles Cirsium edule Cirsium brevistylum
Poison Hemlock (Conium maculatum) Leaves ferny, parsley-like • Stems round and hollow, with purplish blotches • Acutely toxic when ingested; causes skin irritation 6 to 10 feet tall in 2nd year
http://www.uwyo.edu/CES/WYOWEED/ Poison Hemlock
English Holly (Ilex aquifolium) • Tree 15 to 50 feet tall and 15 feet wide • Bark smooth and gray • Leaves glossy, persistent, dark green, wavy and spiny • Flowers are small and white • Berries are bright red or orange and found in small bundles like the flowers
English or Atlantic Ivy(Hedera hibernica, H. helix) Ivy leaves are evergreen, lobed, dull green, with light veins