Starry Stonewort

Scientific name: Nitellopsis obtusa What Is It? Starry stonewort is an aquatic, grass-like algae that spreads rapidly and alters water chemistry. It may be found in both freshwater and estuarine environments. Is It Here Yet? No. However, it is a very harmful invasive species elsewhere in the United States, such as Michigan, and has the […]

September 18, 2019

Scientific name: Tribulus terrestris What Is It? Puncturevine is a small, typically low-growing annual plant that produces sharp, spine-covered fruits that contain seeds. The fruits split further into five smaller sections that each contain seeds and have two prominent spines and several smaller prickles. It is often found in disturbed areas such as pastures, roadsides, […]

August 13, 2019
Poison Hemlock

Scientific name: Conium Maculatum What Is It? Poison hemlock is an acutely toxic plant that, if ingested, can kill humans and animals within a few hours. It may be found in a wide range of areas including fields, roadsides, gardens, and trails or in drier parts of the state, near ditches or other sources of […]

August 12, 2019
Flowering Rush

Scientific name: Butomus umbellatus What Is It? Flowering rush is a perennial freshwater aquatic plant that grows in lakes, rivers, and wetlands. It spreads quickly through bulbils (small bulb-like structure), and fragments of the rhizomes (a type of underground stem). Is It Here Yet? It is established in the upper Columbia River watershed, the lower […]

August 12, 2019

Scientific name: Tamarix ramosissima What Is It? Saltcedar is an aggressively invasive shrub or small tree. It typically grows in wet and salty soils. It is native to southern Europe, north Africa, and south Asia, and was introduced to the United States as a garden ornamental. Is It Here Yet? Yes. Saltceder has been documented […]

August 8, 2019

What Are They? Knapweeds, such as bighead, black, brown, diffuse, meadow, spotted, and vochin knapweeds, are perennials, native to Europe. They grow very aggressively and quickly can infest an area if left unchecked. Are They Here Yet? Yes. Knapweeds are found in various parts pf Washington. Why Should I Care? Knapweeds may impair wildlife habitat, […]

August 6, 2019
Japanese Knotweed

Scientific name: Polygonum cuspidatum What Is It? Japanese knotweed, an escaped ornamental, is a shrubby perennial that was first introduced in the United States from Asia. It grows very aggressively along roadways, neglected gardens, streambeds, and in moist, wet places. Is It Here Yet? Yes. It can be found throughout Washington. Why Should I Care? […]

August 6, 2019
Common Reed

Scientific name: Phragmites australis What Is It? Common reed, also known as phragmites, is a large perennial grass or reed with creeping rhizomes. It typically grows in or near wetlands but also may be found in sites that hold water, such as roadside ditches and depressions. Phragmites form dense stands, which include both live stems […]

August 5, 2019
Common Crupina

Scientific name: Crupina vulgaris What Is It? Crupina is an erect plant that grows to be 1-3 feet tall. It can grow in a wide range of conditions. Dense stands of common crupina can out-compete native plants and decrease foliage for livestock. It is native to southern Europe. Is It Here Yet? Yes, a single […]

August 5, 2019
Garlic Mustard

Scientific name: Alliaria petiolata What Is It? Garlic mustard is single-stalked plant, which typically grows to about 3 feet tall with small white flowers near the top. It is found in forested areas. Garlic mustard is a shade tolerant, invasive species with the capability to establish in our state. Garlic mustard is difficult to control […]

August 2, 2019

Scientific name: Hydrilla verticillata What Is It? Hydrilla is an aquatic plant native to Asia, Africa, and Australia. It was introduced to Florida in the 1950s through the aquarium trade. It is a tenacious weed that has several ways to propagate: seeds, plant fragments, tubers, and turions (a type of bud). It is considered one […]

August 2, 2019

Scientific name: Pueraria montana var. lobata What Is It? This Asian native first became popular in the southern United States, where it was planted on people’s porches. It now is known commonly as the vine that ate the south. Kudzu is a perennial, trailing vine that can grow up to 1 foot a day and […]

August 2, 2019
Leafy Spurge

Scientific name: Euphorbia esula What Is It? Leafy spurge is an erect plant that grows up to 3 feet tall, with yellow flowers. It can survive in a wide variety of conditions, but spreads most successfully in areas that have been grazed. Leafy spurge can dramatically reduce the livestock carrying capacity on pasture and rangelands. […]

August 2, 2019

Scientific name: Myriophyllum aquaticum What Is It? Parrotfeather is a bright green aquatic plant with leaves that grow above the water and resemble tiny fir trees. It grows in slow moving rivers, ditches, and shallow freshwater lakes and ponds, as well as on wet soil along shorelines. Parrotfeather rapidly forms dense mats of vegetation that […]

August 2, 2019
Purple Loosestrife

Scientific name: Lythrum salicaria What Is It? Purple loosestrife is a tall, perennial wetland plant with reddish-purple flowers, which may be found in sunny wetlands, wet meadows, river and stream banks, ponds edges, reservoirs, and ditches. It is native to Europe and Asia, and is responsible for a considerable amount of the degradation to wetlands […]

August 2, 2019
Rush Skeletonweed

Scientific name: Chondrilla juncea What Is It? Rush skeletonweed is a dandelion-like perennial weed that is native to Eurasia. It thrives in sunny areas with dry, sandy to gravelly soils. Its taproots can grow over 8 feet deep, making it difficult to remove. It can propagate through its numerous seeds, lateral-growing roots that can sprout […]

August 2, 2019
Scotch Broom

Scientific name: Cytisus scoparius What Is It? Scotch broom is an upright shrub in the pea family, with yellow flowers. It grows primarily in open, dry meadows and along roads. Scotch broom crowds out native species and negatively impacts wildlife habitat. It is native to Europe. Is It Here Yet? Yes, Scotch broom has been […]

August 2, 2019
Variable Leaf Milfoil

Scientific name: Myriophyllum heterophyllum What Is It? Variable-leaf milfoil is a submersed, rooted, perennial, aquatic plant that is native to the eastern United States. It has both underwater and emergent leaves with dark red to reddish brown stems. It is found in freshwater lakes, ponds, and slow moving rivers. Is It Here Yet? Yes, variable-leaf […]

August 2, 2019
Yellow Starthistle

Scientific name: Centaurea solstitialis What Is It? Yellow starthistle is a plant that grows to be 1-3 feet tall, with yellow, thistle-like flowers. It grows in rangeland, edges of cropland, abandoned farmlands and pastures, roadsides, railways, and recreational areas. Yellow starthistle can poison and kill horses. Is It Here Yet? Yes. Yellow starthistle is widespread […]

August 2, 2019
Caulerpa Seaweed

Scientific name: Caulerpa taxolia What Is It? Caulerpa is native to the Caribbean Sea and the Indian Ocean. It is a bright green, marine alga popular as a saltwater aquarium specimen. Called “killer algae,” it is known as the algae that took over the Mediterranean Sea. Is It Here Yet? No, but California recently spent […]

August 1, 2019
Brazilian Elodea

Scientific name: Egeria densa What Is It? Brazilian elodea is a bright green, robust, freshwater plant originally sold in Washington pet stores for aquariums. It roots at the bottom of freshwater bodies, with highly branched stems that grow up in 18 feet to the water surface. As its name suggests, it is a South American […]

August 1, 2019
Butterfly Bush

Scientific name: Buddleia davidii What Is It? The butterfly bush is a perennial, woody shrub with purple flowers. It is a very popular ornamental plant, often found in gardens. It also is common along riverbanks and river gravel bars where it out-competes native plants and alters soil nutrients. Is It Here Yet? Yes. Escaped, invasive […]

July 31, 2019
Spartina Cordgrass

Scientific name: Spartina alterniflora What Is It? Spartina species are aquatic grasses that grow on the mudflats and marshes of Puget Sound and coastal estuaries. The plants tend to grow in circular clumps called ‘clones’ and are bright green in color. Smooth cordgrass came to Washington in the late 1800s, either in shipments of oysters […]

July 30, 2019
Scotch Thistle

Scientific name: Onopordum acanthium What Is It? Scotch thistle was introduced to the United States as an ornamental in the 1800s. It can grow up to 8 feet tall and 5 feet wide, with small pink-purple flowers. It is native to Europe and Asia. Is It Here Yet? Yes, Scotch thistle has been documented in […]

July 30, 2019
Eurasian Watermilfoil

Scientific name: Myriophyllum spicatum What Is It? Eurasian watermilfoil is a submersed plant that grows in a variety of still and flowing freshwater bodies. It can tolerate a range of salinity, acidity, and temperature. Watermilfoil forms dense mats that shade native aquatic plants, inhibit water flow, and hamper recreation Is It Here Yet? Yes. Eurasian […]

July 24, 2019