Enemies at the Gate: “New” Weeds in the Portland Metro Region Dominic Maze, Biologist/Inv Spp. Coordinator Bureau of Environmental Services Feb. 4, 2015 Clackamas Comm. College Invasive Plant Impacts Impair water quality/ quanEty • Alter Hydrology (flow, erosion, intercepEon, turbidity, nutrient cycling, etc.) • EstablisHed populaons = more herbicides • Green infrastructure/ Japanese knotweed along a stream. faciliEes Environmental Services l “New” Weeds 2 Invasive Plant Impacts • Rate of Spread/Dominance • Create monocultures • CHange successional processes (early seral - “inv. apex”) • Homogenize structure (above and below ground) • Limit resources for nave species (other plants, salmonids, avian, etc...) Environmental Services l “New” Weeds 3 Species we are treang... • For restoraon (widespread) – IrisH and EnglisH ivies – Old man’s beard – EnglisH Hawthorn – EnglisH laurel – English holly – Reed Canary grass – Yellow flag iris – Blackberries – Many others, small scale Environmental Services l “New” Weeds 4 “New” Invasive Plant Species • Uncertain distribuEon for these • Most are (likely) centered in PDX/SeaTac region • Leaving out beaer known, locally abundant species (garlic mustard, spurge laurel) • Coming soon to a area near you? Environmental Services l “New” Weeds 5 Species we are treating... • “EDRR” EDRR NEWBIES – Garlic mustard – Drooping sedge – Purple loosestrife – Goatsrue – False brome – Impa+ens spp. – Knotweeds – ‘Coltsfoots’ (coltsfeet?) – Centaurea spp. – Japanese angelica tree – Common reed – Yellow arcHangel – Ludwigia spp. – Spurge laurel – Oblong spurge – Milk thistle – Hawkweeds – Giant Hogweed – Lesser celandine – Pokeweed – Purpletop vervain Environmental Services l “New” Weeds 6 Species we are treating... • EDRR EDRR NEWBIES – Garlic mustard – Drooping sedge – Purple loosestrife – Goatsrue – False brome – Impa+ens spp. – Knotweeds – ‘Coltsfoots’ (coltsfeet?) – Centaurea spp. – Japanese angelica tree – Common reed – Yellow arcHangel – Ludwigia spp. – Spurge laurel – Oblong spurge – Milk thistle – Hawkweeds – Giant Hogweed – Lesser celandine – Pokeweed – Purpletop vervain Environmental Services l “New” Weeds 7 Ludwigia species Onagraceae Do I have Ludwigia? • Ludwigia peploides ssp. • Is your wetland, pond, irrigation peploides (invasive) ditch, etc choked with a showy, yellow-flowered plant with reddish • Ludwigia peploides ssp. stems? montevidensis: floating primrose willow, marsh purslane (invasive) • Ludwigia hexapetela false loosetrife, water primrose (invasive) • Ludwigia palustris marsh seedbox, marsh primrose-willow Cal-IPC (native; no concern) Is it native or not? Photo: Mike Jones • Leaves opposite = native Environmental Services l “New” Weeds • Leaves alternate/showy flowers = not8 Ludwigia species • Fill in slow moving waters • Riparian zones • Clog intakes, outflows • Large amount of roots • Spreads vegetatively and by seed (less common) • Sporadic patches in the WV • Determining distribution of these species is a top priority! Environmental Services l “New” Weeds 9 Ludwigia Control What is my threshold? Mechanical • aquatic species difficult to treat, § material should be removed from can have drastic impacts on water shorelines, water surface and cleared quality and habitat from outfall areas. • most aquatic systems “open” • this should occur when water levels new material (plant parts, are lowest and seed hasn’t set herbicide residues, etc.) can enter and leave • pile on site away from water. • easy to violate standards • consider screening outfall • but... attempts should be made to control Environmental Services l “New” Weeds 10 Goatsrue Fabaceae (Galega officinalis L.) • HigHly invasive – Massive perennial root crowns – Prolific seeder • Habitat modifier • Previously “eradicated” in OR • Toxic • Medicinal • “A” designated OR/ Class “A” WA/ Federal Noxious 1981 • MA, MN, NV, NC, PA, SC, VT Environmental Services l “New” Weeds 11 Goatsrue • From the Middle East • CacHe Co, UT=60+ sq. mi • Other reports... • Cropland, fence-lines, pastures, roadsides, water- ways, and grasslands – [our most valuable pasture Bob Barret lands] • Adapted to acid soils but broad tolerance • ParEcularly lethal to sHeep • Small long-lived seeds easily dispersed Environmental Services l “New” Weeds 12 Goatsrue Identification --hollow stem --pale pink pea- flowers Environmental Services l “New” Weeds 13 Goatsrue Identification Environmental Services l “New” Weeds 14 Goatsrue Identification --7-15 leaflets with --small skinny pods that pointy tips; NO twist when dry tendrils! Environmental Services l “New” Weeds 15 Impatiens spp. Balsaminaceae • WHat species do I Have and wHat do I do with it? • Large genus with many invasives, hybrids – Massive annual biomass – Prolific seeder (and roots at nodes) – “melts away” • I. capensis • I. balfourii • I. glandulifera • I. parviflora • others? (I. bicolor) Environmental Services l “New” Weeds 16 Impatiens spp. • I. capensis (NOT nave!) Environmental Services l “New” Weeds 17 Impatiens spp. • I. capensis (NOT nave!) • I. glandulifera Environmental Services l “New” Weeds 18 Impatiens spp. • I. balfourii • I. bicolor (new to Americas!) Environmental Services l “New” Weeds 19 Impatiens spp. • I. parviflora (new to OR) Environmental Services l “New” Weeds 20 Impatiens spp. • I. parviflora Environmental Services l “New” Weeds 21 Impatiens spp. • I. parviflora Environmental Services l “New” Weeds 22 Impatiens spp. • As these Impa+ens spp. are annuals, mucH can be done with smaller, new populaons and elbow grease. • But it is more difficult with larger infestaons with large seed banks. • ResearcH Has sHown that the seeds of many Impaens spp. are not long-lived. NATIVE I. noli-tangere & I. ecornuta; courtesy of P. Zika Environmental Services l “New” Weeds 23 Coltsfoots (Coltsfeet?) Asteraceae • AKA “buaerburs” • Four species in the PNW • CHaracterisEcs – Bloom first – Herbaceous perennials – Moist, open disturbed areas – Deep rHizomes – Seed and vegetave spread • One nave; three HigHly invasive – Petasites frigidus (nave) – Petasites fragrans – Petasites japonicus – Tussilago farfara Native sweet coltsfoot; pictures Jordan Jackson Environmental Services l “New” Weeds 24 Coltsfoot • Petasites japonicus – Japanese buaerbur aka, elepHant ear, fuki, bog rHubarb – BIG! – Toxic (as are the others) – Not on OR or WA state lists – Larry1940 “...Hardy in Portland, Oregon, mine Have survived in pots with temperatures down to 16 F. THey can be invasive, I double poaed one in the ground, and it sEll escaped.” • In THurston & Skagit Co., WA • Portland Top picture, Ben Legler Environmental Services l “New” Weeds 25 Coltsfoot • Petasites japonicus – Japanese buaerbur aka, elepHant ear, fuki, bog rHubarb – BIG! – Toxic (as are the others) – Not on OR or WA state lists – Larry1940 “...Hardy in Portland, Oregon, mine Have survived in pots with temperatures down to 16 F. THey can be invasive, I double poaed one in the ground, and it sEll escaped.” • In THurston & Skagit Co., WA • Portland Environmental Services l “New” Weeds 26 Coltsfoot • Petasites fragrans – Winter Heliotrope – One pop, banks of the Willameae in Corvallis – Dense, rapidly expanding growth – No OR, WA lisEng • Tussilago farfara – Similar leaves to P. fragrans (but no serrate margin) – OR Rank “A”, no WA – Present PDX; King, THur, Sno Co; BC, Vancouver Is. • “Early successional”: mecHanical not recommended; decrease disturbance, don’t allow seeding Environmental Services l “New” Weeds 27 Drooping sedge • Carex pendUla – AKA Hanging, pendulous, weeping sedge – Looks (unfortunately) like C. obnupta – Rapidly spreading out and downstream from culEvaon – Seale, PDX-similar climates in NZ very problemac – Great control 2% gly Environmental Services l “New” Weeds Bottom right photo: J C Schou 28 Drooping sedge • Carex pendUla – Looks (unfortunately) like Carex obnupta BottomEnvironmental Services l “New” Weeds left photo: Dave Brigante Bottom right photo: J C Schou 29 Japanese angelica tree • Aralia elata – Related to EnglisH/IrisH ivy – Massive problem in deciduous woods, NE US – Birds spreading fruit – Limited in Portland area Environmental Services l “New” Weeds 30 Japanese angelica tree • Control – “thousands” of seedlings per plant – Seed-bank takes years to deplete – Oak, asH ecosystems prime target – CHemical and mecHanical in PA Environmental Services l “New” Weeds Pictures, Sean Solomon 31 Japanese angelica tree • Control – “thousands” of seedlings per plant – Seed-bank takes years to deplete – Oak, asH ecosystems prime target – CHemical and mecHanical in PA Environmental Services l “New” Weeds Pictures, Sean Solomon 32 Oblong Spurge • Euphorbia oblongata (eggleaf spurge) • sometimes hairy, sometimes not (“ours” not) • up to 1m high • woody, running roots • milky, caustic sap (toxic) • “oblong” leaves • OR “A” ranked Environmental Services l “New” Weeds 33 Oblong Spurge • Euphorbia oblongata (eggleaf spurge) • sometimes hairy, sometimes not (“ours” not) • up to 1m high • woody, running roots • milky, caustic sap (toxic) • “oblong” leaves • OR “A” ranked Environmental Services l “New” Weeds 34 Oblong Spurge • Euphorbia oblongata (eggleaf spurge) • sometimes hairy, sometimes not (“ours” not) • up to 1m high • woody, running roots • milky, caustic sap (toxic) • “oblong” leaves • OR “A” ranked Environmental Services l “New” Weeds 35 Pokeweed Phytolaccaceae Phytolacca americana Environmental Services l “New” Weeds 36 Pokeweed Smooth, hollow Leaves opposite, purplish stem simple and entire Photo by Dr. John Meade, weed scientist emeritus