(Centaurea stoebe) (Linaria vulgaris) Our forests are vulnerable to stresses from insects and disease, invasive species, Plant: This is a short-lived Plant: Yellow toadflax is a uncharacteristic fire, and climate change. perennial that grows from perennial plant introduced two inches to four feet to North America as an As new threats emerge and old threats high. The plant has a ornamental. Unlike Dalmatian resurface, the Helena National Forest is strong taproot and lateral toadflax, yellow toadflax only actively developing new tools to anticipate roots. Flowers are grows to a height of one to and educate on emerging forest threats. surrounded by oval bracts two feet and plants have We hope this will help you to identify some with black tips. One plant multiple stems. Leaves are of the noxious weeds that threaten our natural produces up to 300 flower numerous, pale green to gray- resources and encourage you to learn more heads, producing up to green in color, always about healthy land management practices. 140,000 seeds. Flowers narrow and pointed at both ends, have smooth margins bloom in summer and are alternate on the stem. The showy, snapdragon and resemble both Canada type flower grows on stalks in dense clusters of fifteen to For more information, please go to thistle and bachelor button. twenty at the ends of the stems. Flowers are pale to bright www.mtweed.org or contact the Reproduction is primarily yellow with orange throats and a downward pointing yellow Helena National Forest at by seed, but shoots can start from a root. Spotted spur. Plant produces up to 30,000 seeds annually and has 406-449-5201 Knapweed produces a toxin called “catechin" that an extensive horizontal root system and reproduces eradicates plants around it. through creeping roots or seed. Produced by the Habitat: This is a highly adaptable plant and found Habitat: A variety of areas including rangeland, pastures, Montana Discovery Foundation nearly everywhere in Montana. It will thrive in sunny, arid forests, right-of-ways, cultivated fields, and gravel pits. in partnership with the Helena National Forest conditions in course soil and especially in disturbed areas. 2880 Skyway Drive Treatment: herbicide, biocontrol, hand pulling and Hand pulling can be effective against spotted knapweed and targeted grazing. It has seven different biocontrol insects houndstongue because they have tap roots. The noxious weeds Helena MT 59602 released to manage the plant. with extensive and/or rhizomatous root systems are not well controlled by hand pulling; these include Dalmation and The USDA Forest Service is an equal opportunity employer yellow toadflax and Canada thistle.

(Centaurea stoebe) (Linaria vulgaris) Our forests are vulnerable to stresses from insects and disease, invasive species, Plant: This is a short-lived Plant: Yellow toadflax is a uncharacteristic fire, and climate change. perennial that grows from perennial plant introduced two inches to four feet to North America as an As new threats emerge and old threats high. The plant has a ornamental. Unlike Dalmatian resurface, the Helena National Forest is strong taproot and lateral toadflax, yellow toadflax only actively developing new tools to anticipate roots. Flowers are grows to a height of one to and educate on emerging forest threats. surrounded by oval bracts two feet and plants have We hope this will help you to identify some with black tips. One plant multiple stems. Leaves are of the noxious weeds that threaten our natural produces up to 300 flower numerous, pale green to gray-green in color, always resources and encourage you to learn more heads, producing up to narrow and pointed at both ends, have smooth margins about healthy land management practices. 140,000 seeds. Flowers and are alternate on the stem. The showy, snapdragon bloom in summer and type flower grows on stalks in dense clusters of fifteen to resemble both Canada twenty at the ends of the stems. Flowers are pale to bright thistle and bachelor button. For more information, please go to yellow with orange throats and a downward pointing yellow www.mtweed.org or contact the Reproduction is primarily spur. Plant produces up to 30,000 seeds annually and has Helena National Forest at by seed, but shoots can start from a root. Spotted an extensive horizontal root system and reproduces 406-449-5201 Knapweed produces a toxin called catechin" that through creeping roots or seed. eradicates plants around it. Habitat: A variety of areas including rangeland, pastures, Produced by the Habitat: This is a highly adaptable plant and found forests, right-of-ways, cultivated fields, and gravel pits. Montana Discovery Foundation nearly everywhere in Montana. It will thrive in sunny, arid Treatment: herbicide and biocontrol. in partnership with the Helena National Forest conditions in course soil and especially in disturbed areas. Treatment: herbicide, biocontrol, hand pulling and Hand pulling can be effective against spotted knapweed, 2880 Skyway Drive targeted grazing. It has seven different biocontrol insects houndstongue because they have tap roots. The noxious weeds Helena MT 59602 released to manage the plant. with extensive and/or rhizomatous root systems are not well controlled by hand pulling; these include Dalmation and The USDA Forest Service is an equal opportunity employer yellow toadflax and Canada thistle. (Cirsium arvense) (Cynoglossum officinale) (Linaria dalmatica) (Leucanthemum vulgare) Plant: Canada Plant: A biennial forb with Plant: Like its thistle can reach deep tap roots. The rosette close cousin Plant: An heights of four leaves resemble a dogs yellow toadflax, herbaceous feet and forms tongue in shape. Leaves are Dalmatian toadflax perennial with deep, extensive alternate, up to one foot in produces showy numerous stems root systems, length and up to three inch- snapdragon-type from 1-3 ft. tall. making it difficult es wide and are soft and yellow flowers, Stems are to control. velvety. Plants can grow up however, it is easier slender, erect, Creeping horizontal roots sprout new plants and can to four feet in height. to identify due to its long, erect appearance and waxy and may emerge from the root crown reach more than nineteen feet in one season. These Flowers are five petaled, coating. Dalmatian toadflax has a tap root that can go as or singly from an upturned rhizome. Stalked basal roots can also go as deep as twenty two feet. Rosettes reddish-purple in color with deep as ten feet, but will also produce lateral roots that leaves are spoon-shaped and broadly toothed. Stem are smooth, have irregular lobes and have spine tipped four triangular, rounded can extend out from the parent plant for ten to twelve feet. leaves are alternate, smooth, glossy, and dark green. edges. Thistle leaves are distinctive as they are thorny, seeds which bloom in June Leaves are heart shaped and clasp the stem alternately. The leaf stalks are short and clasp the stem. Solitary alternate and deeply lobed. Leaves are lance-shaped and July. Seeds are sticky, Blooms are nearly identical to yellow toadflax flowers. flower heads are composed of 15-30 white ray florets and the edges have yellowish spines. Stems can grow small brown nutlets. The Flowering occurs from mid-summer to early fall. Seeds surrounding a compact yellow disc with a depressed tall, are often branched, slightly hairy, and lack spines. entire plant has soft white can remain viable for up to ten years and each plant can center. Flowers occur singly at the ends of stems and Canada thistle flowers tend to be smaller than other hairs on it. The single tap root produce up to 500,000 seeds annually. It reproduces by bloom from June to August. A typical plant produces thistle species. One plant is capable of producing over is thick, black and woody. It reproduces from seed only seed and by root. over 500 seeds that spread by wind or animals and 3,000 seeds annually. This plant reproduces by both and each plant can produce up to 2,000 seeds. The plant Habitat: Typically found along disturbed sites, roadsides, remain viable in the seed bank for 2-3 years. The root seed and root, but primarily from the roots. dies after its second year. clear cuts, transitional forest-grassland, right-of-ways, fenc- system is comprised of shallow, unbranched roots Habitat: Abandoned fields or lots, abandoned gravel Habitat: Prefers well drained, relatively sandy and es, cultivated fields, pastures, and rangelands. and rhizomes. pits, pastures, right-of-ways , roadsides, railway gravelly soils; also found in shady areas and under the Treatment: herbicide, targeted grazing, and biocontrol. Habitat: Adapted to coarse and medium textured embankments, lawns, gardens, and agricultural fields. canopy of forests and wetter grasslands. soil; common in native grasslands, pastures, disturbed Treatment: herbicide, biocontrol, cutting. Treatment: cutting/mowing, herbicide, hand pulling, areas, open woods, meadows, and roadsides. mechanical. Plant carries an alkaloid poison that can Treatment: cutting/mowing, herbicide, hand pulling, kill livestock through loss of production of liver cells. mechanical.

(Leucanthemum (Cirsium arvense) (Cynoglossum officinale) (Linaria dalmatica) vulgare)

Plant: Canada Plant: A biennial forb with Plant: Like its Plant: An thistle can reach deep tap roots. The rosette close cousin herbaceous heights of four leaves resemble a dogs yellow toadflax, feet and forms perennial with tongue in shape. Leaves are Dalmatian toadflax numerous stems deep, extensive alternate, up to one foot in produces showy root systems, from 1-3 ft. tall. length and up to three inch- snapdragon-type Stems are making it difficult es wide and are soft and yellow flowers, to control. slender, erect, velvety. Plants can grow up however, it is easier and may emerge Creeping horizontal roots sprout new plants and can to four feet in height. to identify due to its long, erect appearance and waxy reach more than nineteen feet in one season. These from the root crown Flowers are five petaled, coating. Dalmatian toadflax has a tap root that can go as or singly from an upturned rhizome. Stalked basal roots can also go as deep as twenty two feet. Rosettes reddish-purple in color with deep as ten feet, but will also produce lateral roots that are smooth, have irregular lobes and have spine tipped leaves are spoon-shaped and broadly toothed. Stem four triangular, rounded can extend out from the parent plant for ten to twelve feet. leaves are alternate, smooth, glossy, and dark green. edges. Thistle leaves are distinctive as they are thorny, seeds which bloom in June Leaves are heart shaped and clasp the stem alternately. alternate and deeply lobed. Leaves are lance-shaped The leaf stalks are short and clasp the stem. Solitary and July. Seeds are sticky, Blooms are nearly identical to yellow toadflax flowers. flower heads are composed of 15-30 white ray florets and the edges have yellowish spines. Stems can grow small brown nutlets. The Flowering occurs from mid-summer to early fall. Seeds tall, are often branched, slightly hairy, and lack spines. surrounding a compact yellow disc with a depressed entire plant has soft white can remain viable for up to ten years and each plant can center. Flowers occur singly at the ends of stems and Canada thistle flowers tend to be smaller than other hairs on it. The single tap root produce up to 500,000 seeds annually. It reproduces by thistle species. One plant is capable of producing over bloom from June to August. A typical plant produces is thick, black and woody. It reproduces from seed only seed and by root. over 500 seeds that spread by wind or animals and 3,000 seeds annually. This plant reproduces by both and each plant can produce up to 2,000 seeds. The plant Habitat: Typically found along disturbed sites, roadsides, seed and root, but primarily from the roots. remain viable in the seed bank for 2-3 years. The root dies after its second year. clear cuts, transitional forest-grassland, right-of-ways, fenc- system is comprised of shallow, unbranched roots Habitat: Abandoned fields or lots, abandoned gravel Habitat: Prefers well drained, relatively sandy and es, cultivated fields, pastures, and rangelands. pits, pastures, right-of-ways , roadsides, railway and rhizomes. gravelly soils; also found in shady areas and under the Treatment: herbicide, targeted grazing, and biocontrol. Habitat: Adapted to coarse and medium textured embankments, lawns, gardens, and agricultural fields. canopy of forests and wetter grasslands. Treatment: herbicide, biocontrol, cutting. soil; common in native grasslands, pastures, disturbed Treatment: cutting/mowing, herbicide, hand pulling, areas, open woods, meadows, and roadsides. mechanical. Plant carries an alkaloid poison that can Treatment: cutting/mowing, herbicide, hand pulling, kill livestock through loss of production of liver cells. mechanical.