Weed Ranking Project
Alaska Natural Heritage Program

major funding from
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Alaska's Most Wanted Invasive Species

Centaurea stoebe
Centaurea stoebe,
spotted knapweed,
invasive rank score 86


 
Lythrum salicaria
Lythrum salicaria,
purple loosestrife,
invasive rank score 83
 
Melilotus alba
Melilotus alba,
White sweetclover,
invasive rank score 80
 
Hieracium caespitosum   
Hieracium caespitosum,
meadow hawkweed,
invasive rank score 79

 
Bromus tectorum
Bromus tectorum
,
cheatgrass,
invasive rank score 78
 
Cirsium arvense
Cirsium arvense,
Canada thistle,
invasive rank score 76
 
Prunus padus
Prunus padus,

European bird cherry,
invasive rank score 74
 
Vicia cracca
Vicia cracca
bird vetch 73
 
Caragana arborescensCaragana arborescens,
Siberian pea shrub,
invasive rank score 66
 
Bromus inermis ssp. inermis
Bromus inermis ssp. inermis,
smooth brome,
invasive rank score 62
 
Phleum pratense
Phleum pratense,
common timothy,
invasive rank score 54



 
Below are two tables. The first table BELOW lists non-native species present in Alaska that were ranked; the second table lists non-native species currently not recorded in Alaska that were ranked (See Carlson & Shephard 2007 for a comprehensive list of non-native vascular plants in the state). The tables were last updated in November 2008. Species without links to ranking or bios are either new or are being re-written.

The ranking tables below are also available below as MS Excel tables.
Non-native species present in Alaska and ranked (Excel table) Non-native species NOT recorded in Alaska and ranked (Excel table)
Non-native species PRESENT in Alaska that were ranked
Species Biography
Risk Assessment Report
Scientific Name
Common Name
Rank
0-100
(low-high)
Climate similarity of Alaska ecogeographic regions and areas where the species occurs
South Coastal
Interior Boreal
Arctic Alpine

Achillea ptarmica L.

sneezewort

46

Yes

Yes

Yes

Alliara petiolata (Bieb.) Cavara & Grande

garlic mustard

70

Yes

No

No

Anthemis cotula L.

Mayweed chamomile, dog fennel

41

Yes

Yes

No

Bromus inermis ssp. inermis Leyss.

smooth brome

62

Yes

Yes

Yes

Bromus tectorum L.

cheatgrass

78

Yes

Yes

Yes

CARA-bio

CARA-rank

Campanula rapunculoides L.

Creeping bellflower

64

Yes

Yes

Yes

Capsella bursa-pastoris (L.) Medik. L.

shepherd's purse

40

Yes

Yes

Yes

Caragana arborescens Lam.

Siberian pea shrub

66

No

Yes

Yes

Centaurea biebersteinii DC

spotted knapweed

86

Yes

Yes

No

Cerastrium fontanum ssp. vulgare (Hartman) Breuter & Burdert

mouse-ear chickweed

36

Yes

Yes

Yes

Cerastrium glomeratum Thill.

sticky chickweed

36

Yes

Yes

Yes

Chenopodium album L.

lambsquarters

37

Yes

Yes

Yes

Cirsium arvense L. Scop.

Canada thistle

76

Yes

Yes

Yes

Cirsium vulgare (Savi) Ten.

bull thistle, common thistle

61

Yes

Yes

Yes

Convulvulus arvensis L.

field bindweed, morning glory

56

Yes

Yes

Yes

Cotula coronopifolia L.

common brassbuttons

42

Yes

No

No

Crepis tectorum L.

narrow-leaf hawk's beard

54

Yes

Yes

Yes

Cytisus scoparius (L.) Link

English broom, Scotch broom

69

Yes

No

No

Dactylis glomerata L.)

orchardgrass

54

Yes

Yes

Yes

Descurainia sophia (L.) Webb ex Prantl.

flixweed

41

Yes

Yes

Yes

Digitalis purpurea (L.)

purple foxglove

51

Yes

Yes

No

Elymus repens (L.) Gould

quackgrass, couchgrass, dog grass

59

Yes

Yes

Yes

Fallopia convolvulus (L.) Á. Löve. (Polygonum convolvulus L. )

black bindweed

50

Yes

Yes

Yes

Fallopia sachalinensis (F. Schmidt) (Polygonum sachalinense F. Schmidt ex Maxim.)

Giant knotweed

87

Yes

Yes

No

Fallopia X bohemica(Chrtek & Chrtková) J. P. Bailey, Watsonia.
(Polygonym
× bohemicum (J. Chrtek & Chrtkova) Zika &
Jacobson [cuspidatum x sachalinense])

Bohemian knotweed

87

Yes

Yes

No

Fallopia japonica (Houttuyn) (Polygonym cuspidatum Sieb. & Zucc.)

Japanese knotweed

87

Yes

Yes

No

Galeopsis bifida Boenn. and G. tetrahit L.

split-lip hemp-nettle

40

Yes

Yes

Yes

Glechoma hederacea L.

ground ivy

48

Yes

Yes

Yes

Gypsophila paniculata L.

baby's breath

57

Yes

Yes

Yes

Hesperis matronalis L.

dame's rocket

41

Yes

Yes

No

Hieracium aurantiacum L.

orange hawksweed, devil's paintbrush

79

Yes

Yes

Yes

Hieracium caespitosum

meadow hawkweed

79

Yes

Yes

Yes

HIUM-rank

Hieracium umbellatum L.

narrow-leaved hawkweed

54

Yes

Yes

Yes

Hordeum jubatum L.

foxtail barley

63

Yes

Yes

Yes

Hordeum murinum ssp. leporinum (Link) Arcang.

leporinum barley, lepor barley

60

No

Yes

No

Hypericum perforatum

St. Johnswort

52

Yes

Yes

Yes

Impatiens glandulifera Royle

ornamental jewelweed

82

Yes

Yes

No

Lappula squarrosa (Retz.) Dumont.

European stickweed, bristly sheepburr

44

Yes

Yes

Yes

Lepidium densiflorum var. densiflorum Schrad.

common pepperweed,

25

Yes

Yes

Yes

L. densiflorum var. elongatum (Rydb.) Thellung.

tall pepperweed

25

Yes

Yes

Yes

Leucanthemum vulgare Lam.

oxeye daisy, white daisy

61

Yes

Yes

Yes

Linaria vulgaris Miller

yellow toadflax, butter and eggs

61

Yes

Yes

Yes

Lolium perenne ssp. multiflorum (Lam.) Husnot

annual ryegrass

41

Yes

Yes

Yes

Lonicera tatarica L.

bush honeysuckle

66

Yes

Yes

No

Lupinus polyphyllus Lindl.

bigleaf lupine, marsh lupine

55

Yes

-

-

Lythrum salicaria L.

purple loosestrife

83

No

Yes

No

Lythrum virgatum L.

spike loostrife

83

No

Yes

No

Matricaria discoidea DC.

disc mayweed, pineappleweed

32

Yes

Yes

Yes

Medicago luplina L.

Black medic

48

Yes

Yes

Yes

Medicago sativa ssp. falcata (L.) Arcang.

Yellow alfalfa

64

Yes

Yes

Yes

Medicago sativa ssp. sativa L.

Alfalfa

59

Yes

Yes

Yes

Melilotus alba Medikus

white sweetclover

81

Yes

Yes

Yes

Melilotus officinalis (L.) Lam

yellow sweetclover, king's crown

69

Yes

Yes

Yes

MYMU-rank

Mycelis muralis (L.) Dumort.

wall lettuce

31

Yes

No

No

Nymphaea odorata ssp. odorata Ait.

white waterlilly

80

Yes

No

No

Phalaris arundinacea L.

reed canarygrass, canarygrass

83

Yes

Yes

Yes

Phleum pratense L.

common timothy

54

Yes

Yes

Yes

Plantago major L.

common plantain

44

Yes

Yes

Yes

Poa annua L.

annual bluegrass

46

Yes

Yes

Yes

Poa compressa L.

Canada bluegrass

39

Yes

Yes

Yes

Poa pratensis L. ssp. pratensis

Kentucky bluegrass

52

Yes

Yes

Yes

Poa pratensis ssp. irrigata (Lindm.) (Lindb.f.)

spreading bluegrass

52

Yes

Yes

Yes

Poa trivalis L.

rough bluegrass

52

Yes

Yes

Yes

Polygonum aviculare L.

prostrate knotweed, yard knotweed

45

Yes

Yes

Yes

Polygonum persicaria L. (Persicaria maculosa Gray)

spotted ladysthumb

47

Yes

Yes

Yes

Polygonum lapathifolium L. or Persicaria lapathifolia (Linnaeus) Gray

curlytop knotweed

47

Yes

Yes

Yes

Prunus padus L.

European bird cherry

74

Yes

Yes

No

Ranunculus repens L.

creeping buttercup

54

Yes

Yes

Yes

Ranunculis acris L.

tall buttercup

54

Yes

Yes

Yes

Rubus discolor Weihe & Nees

Himalyan blackberry

77

Yes

No

No

Rumex acetosella L.

sheep sorrel

51

Yes

Yes

Yes

Rumex crispus L.

curly dock

48

Yes

Yes

Yes

Rumex obtusifolius L. and
R. longifolius DC.

curly dock, bitter dock

48

Yes

Yes

Yes

Saponaria officinalis L.

bouncing-bett

34

-

-

-

Senecio jacobaea L.

ragwort, stinking willie

63

Yes

Yes

Yes

Senecio vulgaris L.

common groundsel, old-man-in-the-Spring

35

Yes

Yes

Yes

Silene noctiflora L.,

night-flowering catchfly

42

Yes

Yes

Yes

Silene latifloila ssp. alba L.

white cockle

42

Yes

Yes

Yes

Silene vulgaris (Moench)

bladder campio

42

Yes

Yes

Yes

Silene dioica L.

Clairville red catchfly

42

Yes

Yes

Yes

Sonchus arvensis L. ssp. uliginosus (Bieb.) Nyman

perennial sowthistle, moist sowthistle

72

Yes

Yes

No

Sorbus aucuparia L.

European mountain ash, rowan

59

Yes

No

No

Spergula arvensis L.

Corn spurry

32

Yes

Yes

No

Stellaria media L. (Vill.) (disturbed sites)

common chickweed

42

Yes

Yes

Yes

Stellaria media L. (Vill.) (sea bird colonies )

common chickweed

54

Yes

Yes

Yes

Tanacetum vulgare L.

common tansy, garden tansy

57

Yes

Yes

Yes

Taraxacum officinale G.H. Weber ex Wigg

common dandelion

58

Yes

Yes

Yes

Tagopogon dubius Scop.

yellow salsify, goat's bear

50

Yes

Yes

No

Trifolium hybridum L.

alsike clover

57

Yes

Yes

Yes

Trifolium pratense L.

red clover

53

Yes

Yes

Yes

Trifolium repens L.

white clover, ladino clover

59

Yes

Yes

Yes

Tripleurospermum perforata (Merat) M. Lainz

scentless false mayweed,
scentless chamomile

48

Yes

Yes

Yes

Verbascum thapsus L.

common mullein

52

Yes

Yes

No

Vicia cracca L.

bird vetch, cow vetch, tufted vetch

73

Yes

Yes

Yes

Vicia villosa Roth

winter vetch

53

Yes

Yes

No

Non-native species NOT recorded in Alaska and that were ranked, but with a high probability of occurring in Alaska. They have been found in Washington state and neighboring Canadian provinces and territories.

Species Biography
Risk Assessment Report
Scientific Name
Common Name
Rank
0-100
(low-high)
Climate similarity of Alaska ecogeographic regions and areas where the species occurs
South Coastal
Interior Boreal
Arctic Alpine

Alnus glutinosa (L.) Gaerth.

European alder, black alder

61

Yes

Yes

Yes

Brachypodium sylvaticum (Huds.) Beauv.

false-brome

70

Yes

Yes

Yes

Carduus nutans L.

musk thistle

61

Yes

Yes

Yes

Carduus acanthoides L.

plumeless thistle

61

Yes

Yes

Yes

Carduus pycnocephalus L.

Italian thistle

61

Yes

Yes

Yes

Carduus tenuiflorus W. Curtis

slender-flowered thistle

61

Yes

Yes

Yes

Crupina vulgaris Cass.

common crupina, bearded creaper

rejected from consideration

No

No

No

Euphorbia esula L.

leafy spurge

84

Yes

Yes

No

Heracleum mantegazzianum Sommier & Levier

giant hogweed

81

Yes

Yes

Yes

Hydrilla verticillata ( L. f) Royle

hydrilla

80

Yes

Yes

Yes

Lepidium latifolium L.

perennial pepperweed, tall whitetop

72

No

Yes

Yes

Linaria dalmatica L.

Dalmatian toadflax

58

No

Yes

No

Myriophyllum spicatum L.

Eurasian watermilfoil

90

Yes

Yes

No

Potentilla recta L.

sulphur cinquefoil

57

Yes

Yes

No

Spartina alterniflora Loisel

Atlantic cordgrass

86

Yes

No

No

Spartina angelica C.E. Hubbard

saltmarsh grass

86

Yes

No

No

Spartina densiflora Brongn.,
S. patens (Ait.) Muhls

saltmarsh grass

86

Yes

No

No

Spartina patens (Ait.) Muhls

smooth cordgrass

86

Yes

No

No

Zostera japonica Aschers. & Graebn.

dwarf eelgrass

53

Yes

Yes

No


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Page updated January 5, 2010 by Susan C. Klein Research and Consulting
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