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Plants
ANS—Plants

Egeria


Description

  • Egeria densa
  • Aquatic plant from South America; imported from the aquarium trade
  • Has few natural predators to keep its growth in check
  • When introduced to a lake it often forms dense mats that displace native aquatic plants
  • These mats are unsightly, interfere with recreation, and degrade fish habitat

General Characteristics

  • similar to hydrilla
  • submersed aquatic weed, found in ponds, lakes, streams and rivers
  • may reach 6 feet in length and are freely branching
  • leaves occur in whorls of 3-6, most commonly of 4
  • individual leaves are 1-1 ¼ inch long, 5 mm wide
  • finally toothed leaf margins
  • undersides of the leaf midribs are smooth and without teeth unlike those of hydrilla
  • flowers have 3 white petals and 3 green sepals
  • flowers appear at water surface on long stalks, showy flowers petals are 1/3 inch long

Hydrilla


Description

Hydrilla. Hydrilla
  • Hydrilla verticillata
  • Introduced from Asia for use in aquariums
  • Spreads by fragmentation and via transport on boats, motors, trailers, fishing nets, and other gear, and aquarium or water garden release
  • Grows thick mats especially in shallow water
  • Quickly takes over shallow lakes and rivers, preventing boating, fishing, hunting, and swimming
  • Clogs irrigation canals

Description

  • difficult to identify, sometimes confuse with Elodea or Egeria
  • sharply toothed leaves in whorls of 3-8
  • sometimes possess small teeth along underside of leaf midrib

Eurasian Watermilfoil


Description

  • Myriopyllum spicatum
  • Spreads by fragmentation, currents and waves, and overland via transport on boats, motors, trailers, fishing nets, and other gear
  • Grows thick mats in waters less than 15 deep
  • Eradication is nearly impossible
  • Can quickly take over shallow lakes and rivers, which can prevent boating, fishing, hunting, and swimming

General Characteristics

  • Submersed, perennial, aquatic plan with feathery leaves arranged in whorls around the stem.
  • Found growing in shallow water to 25 feet deep or more.
  • Tops often turn read in color.
  • Milfoil stems branch several times near the water surface.
  • Erect stalks emerge above water with small reddish flowers.
  • Typically 4, but sometimes 3-5 leaves, form a whorl around the stem.
  • Each leaf has 12 or more pares of leaflets.

Links

US Geological Survey (USGS)--Eurasian Watermilfoil


Curley Pondweed


Description

  • Potamogeton crispus
  • Perennial, rooted, submerged aquatic vascular plant native to Eurasia, Africa and Australia
  • By 1950 most of the U.S. was infested by this species
  • Forms dense mats which interfere with recreation and limit the growth of native aquatic plants
  • In shallow lakes it can grow dense enough to affect recreational boating and fishing
  • It can alter nutrient dynamics of a fertile lake causing heavy summer algae blooms

General Characteristics

  • leaves are alternate with crinkled leaves that are finely toothed
  • most often found in ponds with fertile, hard water
  • flower spikes often stick up above the water surface during spring
  • tolerates low light and may grow in deep water

Flowering Rush


Description

  • Butomus umbellatus
  • An emergent in shallow areas of lakes, flowering rush has umbellate pink flowers and grows to 3 feet tall on triangular stems
  • Also a submersed form which can grow in water 10 feet deep
  • Use as an ornamental provided a route to the Midwest and expedited it’s spread westward to the Idaho panhandle and Northwestern Montana
  • In Northwestern Montana it is reported to be out-competing the native willows and cattails

General Characteristics

  • flowers grow in umbrella shaped clusters and each individual flower has 3 whitish pink petals
  • plants only produce flowers in very shallow water or on dry sites
  • green stems resemble bulrushes but are triangular in cross section
  • leaf tips may be spirally twisted
  • along shores, has erect leaves and grows to about 3 feet in height
  • forms an extensive root system that can break into new plants if disturbed

Purple Loosestrife


Description

  • Lythrum salicaria
  • Imported from Europe in the early 1800’s for its medicinal value and for the ornate purple spikes of the blooming plant
  • Is sold as an ornamental in nurseries in some states
  • Displaces native plants and animals
  • Found in 42 of the contiguous states
  • Extremely difficult to eradicate, although recently biological control agents have been found to be effective

General Characteristics

  • Grows 1 to 8 feet tall
  • Stems are 4-sided, and multibranched
  • Leaves 4 inches long or less, lance-shaped and pointed
  • Flowers are 1 inch in diameter, magenta-colored, and have 5-7 wrinkled petals

Salt Cedar


Description

  • Tamaricaceae spp.
  • This invasive small tree or shrub remains a popular ornamental
  • One mature plant can produce ½ million seeds each year
  • Reproduces by wind and water borne seeds, and vegetatively
  • Can use up to 200 gallons of water a day, reducing and even eliminating water flow
  • Out-competes native plant communities, degrades wildlife habitat and has resulted in the decline of many species
  • Reduces recreational and agricultural use, and increases wildfire frequency

General Characteristics

  • 5 to 20 feet tall shrubby tree
  • Smooth woody stems are reddish brown, turning gray and cracked as tree ages
  • Leaves are small and scale-like
  • Flowers are pink to white and feather-like

Yellow Flag Iris


Description

  • Iris pseudacorus
  • Rhizomatous immersed wetland forb
  • Propagates by both seed and underground rhizomes
  • The drought tolerant rhizomes break off, and spread downstream, as does the seed
  • Fast growing, fast spreading, and very competitive
  • Forms almost impenetrable thickets
  • Brought into the U.S. as an ornamental, has been used for erosion control, a dye and fiber plant, and in sewage treatment cells
  • Well established in Lake, Sanders, Missoula, and Flathead counties

General Characteristics

  • Very showy yellow iris flowers with 3 downward pointing and 3 upward pointing petals
  • Fruit is a 3 sided angled cylindrical capsule 1 to 4 inches long, containing many flat brown seeds
  • 3 to 4 feet tall
  • Long, flat, dark green, sword-like leaves