Why are These Species of Concern?

 

Invasive species are non-native plant species that are capable of out-competing native, desirable species. As a result, this alters the native plant communities and ecosystems around us. They can also reduce crop yields, reduce the value of agricultural products, negatively impact wildlife habitat, poison livestock (species dependent), decrease property value, increase irrigation costs and are a source of plant diseases and insect pests. The invasive species listed below are species of concern because they have the potential to negatively impact Park County’s ecosystems, agricultural processes, and municipal and industrial infrastructure.

Aquatic Species of Concern

Aquatic Invasive Species (AIS) are aquatic plants, animals, or pathogens that are not native to Montana and can cause harm to our environment and economy. AIS are dangerous because they can displace native species, clog waterways, impact irrigation and power systems, degrade ecosystems, threaten recreational fishing opportunities, and can cause wildlife and public health problems.

Noxious weeds listed on the Montana Noxious Weed List are indicated by a (NW) beside their name. The aquatic species listed on our site are not all the invasive species threatening Park County. For a full list of Montana’s aquatic invasive species, see the link below.

More information on aquatic invasive species and how to identify can be found here: MT Aquatic Invasive Species Field Guide

Zebra mussels have not yet been reported in Park County.
 
Zebra mussel (Dreissena polymorpha) is a small (~2 inches), triangular aquatic animal named for the striped pattern of its shell. Color patterns can vary from dark to light colored shells and no stripes. They are typically found in dense clumps attached to objects, surfaces, or other mussels. Zebra mussels can attach to any stable surface in the water column, including rocks, artificial surfaces (cement, steel, rope, etc.), crayfish, clams, and each other.
Photo from fieldguide.mt.gov
New Zealand mudsnails have been reported in Park County.
 
New Zealand mudsnail (Potamopyrgus antipodarum) is a small invasive snail (4-6 mm) with a coiling, elongated shell with 5-6 whorls separated by deep grooves. They are generally a dark brown to grey in color. The New Zealand mudsnail likes to live in springs, spring creeks, and river sections downstream from dams. However, they can also survive in cool lakes with suitable habitat. They are most typically found on larger rocks or on pieces of wood.
Photo from fieldguide.mt.gov

Curlyleaf pondweed has been reported in Park County.

Curlyleaf pondweed (Potamogeton crispus) is an aquatic, incredibly invasive, noxious weed. It has blue-green leaves that are wavy along the edges. The leaves are stiff, crinkled, and approximately 1/2-inch wide and 2-3 inches long. Curlyleaf pondweed prefers to grow in shallow, deep, still or flowing waters.

Photo from fieldguide.mt.gov

Didymo has been reported in Park County.

Didymo (Didymosphenia geminata), or “rock snot,” is actually a native species to Montana, but has been growing at an unusually fast rate and negatively impacting wildlife habitat. Didymo is a type of microscopic algae that likes to cling to river rocks. It likes to grow at the bottom of rivers and creeks and wash zones of lake shores.

Photo from fieldguide.mt.gov

Terrestrial Species of Concern

Invasive terrestrial species include plants, animals, and microorganisms that grow or live on land, are nonnative to Park County’s ecosystem, and cause harm to natural and cultural resources, the economy, and human health. Some terrestrial non-native plants and animals have caused vast damage to Montana’s natural resources as well as its economy. It is important that we do all that is within our power to better protect Montana from new and established invasive species.

Noxious weeds listed on the Montana Noxious Weed List are indicated by a (NW) beside their name. The terrestrial species listed on our site are not all the invasive species threatening Park County. For a full list of Montana’s terrestrial invasive species, see the links below.

More information on terrestrial invasive species and how to identify can be found here:

MT Noxious Weed List

MWCA Weed I.D.

Ventenata has been reported in Park County.

Ventenata (Ventenata dubia) is a noxious weed and invasive grass that is 6 – 27 inches in height. The leaves are rolled length ways or folded and the awns (which encase the seed) are bent. Ventenata plants resemble a pyramid shape. They are commonly found in pastures, range land and roadsides in shallow, rocky, clay and /or clay loam soils. It can grow in elevation up to 5,900 feet.

Photo from fieldguide.mt.gov

Houndstongue has been reported in Park County.

Houndstongue (Cynoglossum officinale) is a noxious weed with velvety rosette leaves with smooth edges and defined veins. The stem leaves alternate with smaller leaves toward the top. Houndstongue produces reddish-purple flowers with 5 petals and burr-like adhesive nutlets/seeds. This plant grows to a height of 8 to 30 inches. Houndstongue prefers to grow in disturbed areas, trails, roadsides, logging areas, abandoned cropland, ranglands, pastures, riparian areas, and borders of wooded areas.

Photo from mtweed.org

Leafy spurge has been reported in Park County.

Leafy spurge (Euphorbia esula) is a perennial noxious weed. They have brown roots with pink buds and alternating, narrow leaves that are 1 to 4 inches long. The strems and leaves contain a milky, latex sap. Leafy spurge has yellow/green flowers and can grow to a height of 1 to 3 feet.

Riparian Species of Concern

In Montana, populations of invasive species have proven their ability to overtake large areas of riparian systems. Riparian habitats are extremely critical for native wildlife health and sensitive to attacks from invasive species. Attempts to control riparian invasive species populations in Montana have been expensive and met with limited success. Early detection and rapid response to riparian invasive species are keys to controlling these weeds.

Noxious weeds listed on the Montana Noxious Weed List are indicated by a (NW) beside their name. The riparian species listed on our site are not all the invasive species threatening Park County. For a full list of Montana’s invasive species, see the links below.

More information on Montana’s invasive species and how to identify can be found here:

MT Noxious Weed List

MWCA Weed I.D.

Yellowflag iris has been reported in Park County.

Yellowflag iris (Iris pseudacorus) is a perennial noxious weed that likes to grow along shorelines, ditches, stream banks, floodplains, forests, areas of shallow water, low-lying wetlands and fish ponds. This iris has three large downward facing yellow petals with brown or purple streaks and dark green leaves in a fan-like arrangement. They typically grow to a height of 3 to 5 feet.

Saltcedar has been reported in Park County.

Saltcedar (Tamarix ramosissima, T. chinensis) is a noxious weed that likes to grow around lake and river shores, irrigation ditches, moist rangelands and other riparian areas. It has slender branches and gray-green foliage resembling juniper leaves. The Saltcedar blooms with pink or white flowers with five petals from March to September in dense, showy clusters. The trees can range in height from 8 to 35 feet.

Photo from mtweed.org

Want to know more?

Click on the links to learn more about the impacts of invasive species in Park County and how to report invasive species in Montana.

This project is funded in part by
Park County Community Foundation.

Are you ready to help prevent the spread of invasive species?

Take the Pledge!

Invasive Species Prevention Pledge

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Invasive species pose one of the greatest threats to biodiversity today, but preventing their spread is easy. This pledge provides the on-ramp for people everywhere to be part of the solution in preventing the spread of invasive species.

- Leah Elwell, Fmr. Executive Director