Project to identify the riparian and aquatic weeds of Montana -vascular plants only.

The asterisks (*) signifies species that are not necessarily weedy, but that have been reported as such in certain instances as recorded by the Agricultural Extension plant identification program at the Montana State University Herbarium. The potential for invasiveness of such species has been validated by field knowledge of the staff at the MSU Herbarium (Matt Lavin, Jack Rumely, and Cathy Seibert), and by reports in published floras that indicate such potential (i.e., Flora of the Pacific Northwest, Intermountain Flora, Aquatic Plants of the Southwest, etc.).

A parenthetical "E" signifies an exotic or introduced species.

Alismataceae - Water Plaintain Family

• *Alisma plantago-aquatica (Water Plantain)
• *Sagittaria cuneata (Arrowhead)

Amaranthaceae - Pigweed Family

• *Amaranthus retroflexus (E) (Pigweed)

Anacardiaceae - Sumac Family

• Toxicodendron rydbergii - Poison Ivy

Apiaceae - Carrot Family

• *Carum carvi (Caraway)
• *Cicuta douglassii (Water Hemlock)
• *Conium maculatum (Poison Hemlock)
• *Daucus carota (E) (Wild Carrot)

Asteraceae - Sunflower Family

• *Arctium minus (E) (Burdock)
• *Bidens cernua (Beggar Ticks)
• *Bidens frondosa (Beggar Ticks)
• *Bidens beckii (Beggar Ticks)
• *Bidens comosa (Beggar Ticks)
• *Conyza canadensis (Conyza)
• Tanacetum vulgare (E) (Tansy)

Balsaminaceae - Touch-me-not Family

• *Impatiens ecalcarata (Touch-me-not)
• *Impatiens glandulifera (Touch-me-not)

Boraginaceae - Borage Family

• *Asperugo procumbens (E) (Catchweed)

Cynoglossum officinale (E) (Hound's Tongue)

• *Myosotis laxa (Forget-me-not)
• *Myosotis micrantha (Forget-me-not)
• *Myosotis scorpioides (Forget-me-not)
• *Plagiobothrys scouleri (Popcorn flower)
• *Plagiobothrys mollis (Popcorn flower)

Brassicaceae - Mustard Family

• *Barbarea orthoceras (Winter Cress)
• *Barbarea incana (Winter Cress)
• *Cardamine occidentalis (Bitter Cress)
• *Herperis matronalis (E) (Sweet Rocket)
• *Nasturtium officinale (Water Cress)
• *Rorippa palustris (Yellow Cress)
• *Rorippa sinuata (Yellow Cress)
• *Subularia aquatica (Alwort)

Callitrichaceae - Water Starwort Family

• *Callitriche stagnalis (Water starwort)

Caprifoliaceae - Honeysuckle Family

• *Lonicera tartarica (E) (Honeysuckle)

Ceratophyllaceae - Hornwort Family

• *Ceratophyllum demersum (Coontail)

Chenopodiaceae - Goosefoot family

• *Salicornia rubra (Saltwort)
• *Sueda calceoliformis (Sea Blite)

Cyperaceae - Sedge Family

• *Carex flava (Yellow sedge)
• *Carex nebrascensis (Nebraska sedge)
• *Carex rostrata (Beaked sedge)
• *Scirpus acutus (Bulrush)
• *Scirpus nevadensis (Bulrush)
• *Scirpus olneyi (Bulrush)

Dipsaceae - Teasel Family

• Knautia arvensis (E) (Field Scabious)

Eleagnaceae - Oleaster Family

• Eleagnus angustifolia (E) Russian Olive

Equisetaceae - Horsetail Family

• *Equisetum arvense (Horsetail or Scouring Rush)
• *Equisetum hyemale (Horsetail or Scouring Rush)
• *Equisetum laevigatum (Horsetail or Scouring Rush)

Haloragaceae - Water Milfoil Family

• Myriophyllum spicatum (Water Milfoil)
• Myriophyllum verticillatum (Water Milfoil)

Hydrocharitaceae (Frog's Bit Family)

• Elodea canadensis (Waterweed)

Iridaceae - Iris Family

• *Iris missouriensis - Common Iris

Juncaceae - Rush Family

• *Juncus buffonius (Annual Rush)
• *Juncus ensifolius (Rush)

Lamiaceae - Mint Family

• *Prunella vulgaris (Selfheal)
• *Stachys palustris (Hedge nettle)

Lythraceae - Loosestrife Family

• Lythrum alatum (E) (Loosestrife)
• Lythrum salicaria (E) (Purple Loosestrife)
• Lythrum virgatumXalatum (E) (Lossestrife)

Nymphaea - Water Lily Family

• *Nuphar polysepalum (Yellow Water Lily)
• *Nymphaea tetragona (White Water Lily)

Plantaginaceae - Plantain Family

• *Plantago elongata (Plantain)

Poaceae - Grass Family

• *Agropyron repens (E) (Quack grass)
• *Agrostis stolonifera (Redtop)
• *Alopecurus arundinacea (E) (Garrison Creeping Foxtail)
• *Beckmannia syzigachne (E) (Slough grass)
• *Bromis inermis (E) (Smooth Brome)
• *Dactylis glomerata (E) (Orchard grass)
• *Echinochloa crusgalli (E) (Barnyard Grass)
• *Glyceria grandis (Mannagrass)
• *Catabrosa aquatica (Brook grass)
• *Holcus lanata (E) (Velvet grass)
• *Muhlenbergia aperifolia (Alkali Muhly)
• *Phalaris arundinacea (Canary Reed grass)
• *Phragmites australis (Giant Reed grass)
• *Poa pratensis (E) (Kentucky Bluegrass)

Polygonaceae - Buckwheat Family

• Polygonum amphibium (Knotweed)
• Polygonum persicaria (Knotweed)
• Polygonum hydropiper (Knotweed)
• Polygonum lapathifolium (Knotweed)

Potamogetonaceae - Pondweed Family

• *Potamogeton gramineus (Pondweed)
• *Potamogeton natans (Pondweed)
• *Potamogeton pectinatus (Pondweed)

Primulaceae - Primrose Family

• Lysmachia thyrsiflora (Loosestrife)

Ranunculaceae - Buttercup Family

• *Ranunculus aquatilis (Water Buttercup)
• *Ranunculus natans (Water Buttercup)

Rosaceae - Rose Family

• *Rosa nutkana - Wild Rose

Rubiaceae - Madder Family

• Galium aparine - Bedstraw

Salicaceae - Willow Family

• *Salix exigua (River Willow, or Sandbar Willow)
• Salix fragilis (E) (Fragile Willow)

Scrophulariaceae - Snapdragon Family

• Linaria vulgaris (E) (Toadflax)
• *Verbascum blattaria (E) (Mullein)
• *Verbascum thapsus (E) (Mullein)
• *Veronica anagallis-aquatica (Water Speedwell)

Tamaricaceae - Tamarisk Family

• Tamarix chinesis (E) (Salt Cedar)

Urticaceae - Nettle Family

• *Urtica dioica (Stinging Nettles)

Zannichelliaceae - Horned Pondweed Family

• *Zannichellia palustris L. (Horned Pondweed)

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