Invasiveness Ranking System for Non-Native Plants of Alaska

EcologicalimpactBiologicalcharacteristicsPlant speciesCommon nameRumex crispus * Curly dock 10 16 14 8 48 48 Yes Yes YesRumex longifolius * Dooryard dock 10 16 14 8 48 48 Yes Yes YesRumex obtusifolius * Bitter dock 10 16 14 8 48 48 Yes Yes YesTripleurospermum perforata Scentless false mayweed 13 13(23) 15 6 47(98) 48 Yes Yes YesPersicaria lapathifolia * Curlytop knotweed 6 16 15(19) 7 44(94) 47 Yes Yes YesPersicaria maculosa * Spotted ladysthumb 6 16 15(19) 7 44(94) 47 Yes Yes YesAchillea ptarmica Sneezeweed 14 12 15 2(3) 43(93) 46 Yes Yes YesPoa annua Annual bluegrass 8 13 18 7 46 46 Yes Yes YesPolygonum aviculare Prostrate knotweed 7 15 16 7 45 45 Yes Yes YesLappula squarrosa European stickseed 10 12 17 5 44 44 Yes Yes YesPlantago major Common plantain 8 13 16 7 44 44 Yes Yes YesCotula coronopifolia Common brassbuttons 14 11(23) 9 7 41(98) 42 Yes – –Silene dioica * Red catchfly 13 9 13 7 42 42 Yes Yes YesSilene latifolia * Bladder campion 13 9 13 7 42 42 Yes Yes YesSilene noctiflora * Nightflowering silene 13 9 13 7 42 42 Yes Yes YesStellaria media/non-seabird sites Common chickweed 10 12 15 5 42 42 Yes Yes YesAnthemis cotula Stinking chamomile 8 12 14 7 41 41 Yes Yes –Descurainia sophia Herb sophia 8 13 18 2 41 41 Yes Yes YesHesperis matronalis Dames rocket 10 10(22) 17 2(7) 39(94) 41 Yes Yes –Lolium perenne ssp. multiflorum Italian ryegrass 14 10 15 2 41 41 Yes Yes YesCapsella bursa-pastoris Shepherd’s purse 7 11 18 4 40 40 Yes Yes YesGaleopsis bifida * splitlip hempnettle 14 9 12(19) 3 38(94) 40 Yes Yes YesGaleopsis tetrahit * brittlestem hempnettle 14 9 12(19) 3 38(94) 40 Yes Yes YesPoa compressa Canada bluegrass 6 10 17 5(7) 38(97) 39 Yes Yes YesChenopodium album Lambsquarters 5 12 15 5 37 37 Yes Yes YesCerastium fontanum ssp. vulgare * Big chickweed 6 8(25) 15(19) 5 34(94) 36 Yes Yes YesCerastium glomeratum * Sticky chickweed 6 8(25) 15(19) 5 34(94) 36 Yes Yes YesSenecio vulgaris Old-man-in-the-Spring 4 12 15 5 36 36 Yes Yes YesSaponaria officinalis Bouncingbet 5(30) 8(22) 12 2(3) 27(80) 34 Yes Yes –Matricaria discoidea Disc mayweed 5 9 15 3 32 32 Yes Yes YesSpergula arvensis Corn spurry 2 11 14 5 32 32 Yes Yes YesMycelis muralis Wall-lettuce 7 11(23) 8 4 30(98) 31 Yes – –Lepidium densiflorum Common pepperweed 1(30) 9(23) 8 4 22(88) 25 Yes Yes YesCentaurea solstitialis Yellow star-thistle – – –Crupina vulgaris Common crupina – – –† = Not known in AK (2006)* = Congeneric species ranked together1 Invasiveness is equal to the Relative Maximum Score, which is equal to the sum of scores from each section divided by the total possible. See pages 10–11.Climate matches to the three ecoregions of Alaska are included (Yes = present or high probability of establishing in the ecoregion, – = absent and low probabilityof establishment). Scores >80 = “Extremely Invasive”, 70-79 = “Highly Invasive”, 60-69 = “Moderately Invasive”, 50-59 = “Modestly Invasive”, 40-49 = “WeaklyInvasive”, and < 40 = “Very Weakly Invasive”.DistributionControlTotalInvasiveness1South CoastalInterior BorealArctic AlpineA-3