Spotted knapweed

Cover of: Spotted knapweed |

Published by U.S. Dept. of Agriculture, Forest Service in [Washington, D.C.?] .

Written in English

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  • Spotted knapweed -- Alaska.,
  • Noxious weeds -- Alaska.

Edition Notes

Book details

Statementprepared by Forest Service, Alaska Region.
SeriesLeaflet R10-TP -- 125.
ContributionsSnyder, Cynthia., Shephard, Michael., United States. Forest Service. Alaska Region.
The Physical Object
Pagination1 folded sheet (12 p.) :
Number of Pages12
ID Numbers
Open LibraryOL16110701M

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Spotted knapweed probably came to this country in the s as a contaminant in commercial seed imports from Eurasia. Life cycle: The seeds are the main form of dispersal. A single square foot of spotted knapweed can produce 5, seeds, which can remain viable for eight years or more.

As spotted knapweed seeds mature in late summer and fall. NUTRIENT VALUE The rosettes and young flowers of spotted knapweed have some nutritive value.

A study by Kelsey and Mihalovich () found that spotted knapweed collected before flowering contained neutral detergent fiber (% in dry weight), ether extract (%), crude protein (%), total non-structural carbohydrates ( %), ash ( to %), in vitro dry.

To support our efforts please browse our store (books with medicinal info, etc.). The common knapweed has the nickname of Hardheads. If you pinch off an old Spotted knapweed book head in the autumn, pull off any loose seed heads, there is a very hard kernel.

If you then carefully split this there is a good chance that there will be a small grub inside. A WEED REPORT from the book Weed Control in Natural Areas in the Western United States Spotted knapweed. mowed at the rosette stage will quickly recover, and mowing too late (after seed set) can disperse seed.

However, mowing at the late bud to early bloom stage will reduce seed production. Spotted knapweed is a biennial or short-lived perennial herbaceous plant that grows two to three feet tall. It can form dense cover in prairies, pastures, and open habitats.

Cattle and other animals avoid eating it so it can cause large reductions in available food for grazing animals. Biological. Spotted Knapweed Centaurea biebersteinii DC. Sunflower family (Asteraceae) NATIVE RANGE Central Europe, east to central Russia, Caucasia, and western Siberia DESCRIPTION Spotted knapweed is a biennial or short-lived perennial.

Its name is derived from the spots formed by black margins on the flower bract tips. Spotted knapweed typically. Knapweed Root Weevil Cyphocleonus achates. We are OPEN for the season. This insect can safely be considered "The King" of spotted knapweed biocontrol. A large, conspicuous insect, it lays its eggs on the top of the knapweed's root crown.

After the eggs hatch, the larvae burrow into the root. spotted knapweed is a perennial, new rosettes are also formed during the summer and spring from established root systems. Spotted knapweed grows 12 to 60 inches tall, is more erect and has more limited branching than diffuse knapweed.

Dead spotted knapweed stems generally remain erect during the winter unless crushed by heavy snow-pack. biological control of six species of knapweeds: 1) spotted knapweed, 2) diffuse knap-weed, 3) squarrose knapweed, 4) meadow knapweed, 5) black knapweed, and 6) brown knapweed.

Spotted knapweed, Centaurea stoebe, is perhaps the most wide-spread species, followed in abundance by diffuse knapweed, C.

diffusa. A third. Executive Office Montana Weed Control Association, Inc. PO BoxTwin Bridges, MT () | () (fax). Spotted knapweed (Centaurea stoebe ssp.

micranthos) is a grassland perennial plant native to Eurasia. It was first recorded in North America in and in Minnesota inlikely introduced as a contaminant of alfalfa seed. Spotted knapweed is able to outcompete other plants by exuding a toxic chemical from its roots. Centaurea stoebe L.

– spotted knapweed Subordinate Taxa. The Plants Database includes the following 1 subspecies of Centaurea stoebe. Click below on a thumbnail map or name for subspecies profiles. Native Introduced Native and Introduced. Centaurea stoebe ssp.

micranthos spotted knapweed. Local Concern: Spotted knapweed is poisonous to other plants, creating barren areas where only knapweed grows.

It is a threat to pastures and dry ecosystems including prairies and dunes. Can be a skin irritant. MORE INFORMATION: Spotted Knapweed Invasive Species Alert - Printable PDF. Spotted knapweed is listed as noxious, prohibited, banned or otherwise regulated in 16 states. Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g., threatened or endangered species, state noxious status, and wetland.

Knapweed is a rather robust plant that can be found in dry, infertile soil, vacant lots, near railroad tracks, roadsides, coastlines and high lime or salt areas.

Knapweed has deeply, lobed, gray-green leaves that get up to 6 inches long in its first year. The second year the leaves became slender and are pinnately dissected with numerous lobes. After several hours of computer and book research, my plant clinic partner and I found a match.

The specimen in question was a knapweed root weevil — cyphocleonus achates. The weevil is a biological control for both diffuse and spotted knapweed, a noxious weed in Central Oregon. Spotted Knapweed Resources.

Displaying 1 to 20 of 31 Search Help. Alaska Exotic Plants Information Clearinghouse (AKEPIC): Species Biography - Spotted Knapweed (Feb 7, ) (PDF | KB) University of Alaska - Anchorage.

Alaska Center for Conservation Science. I dig the spotted knapweed in areas where there isn't much, but I have 10 acres and some of it is solid.

My neighbor doesn't take care of his spotted knapweed, so I have plenty of new plants. I'd like a way to spray with a natural spray instead of Weed killer like Stop Weed (which is actually pretty good because it doesn't kill my good plants).

Spotted knapweed seeds remain viable in soil for more than seven years, and individual spotted knapweed plants can live for as long as nine years. The weed is well adapted to a wide range of habitats including open forests, rangeland, roadsides, pastureland, riparian areas, and ditch banks.

Spotted & hybrid knapweed is a non-native, short-lived perennial forb that reproduces mainly by seed. Spotted knapweed can grow up to seeds per plant annually that are viable for up to 8 years.

The key to distinguishing spotted from other knapweeds is the black-tipped, spiny, involucral bracts (phyllaries) at the base of the flower. Don’t pull spotted knapweed without gloves. “It’s nasty stuff,” he says. Jerry’s 49, a soil scientist for the U.S. Forest Service in Coeur d’Alene, not one to call attention to himself.

Look-alike non-native plants: Spotted knapweed can be confused with diffuse and Russian knapweeds, both of which need to be eradicated.

Control strategies: Removing the entire plant before they go to seed can help with small wear gloves when handling as it is thought that Spotted knapweed may contain a cancer-causing substance.

Handpulling: This is an extremely effective method on small-scale infestations of spotted knapweed. Pulling is easiest when soil is moist; allowing you to remove most of the taproot and kill the plant. Any stage from flowering on should be bagged and removed. Centaurea stoebe, the spotted knapweed or panicled knapweed, is a species of Centaurea native to eastern Europe.

It is also an invasive species in the United States, and particularly widespread in dryer regions of the Pacific Northwest. This species along with Centaurea diffusa are the stereotypical "tumbleweed" of the West- breaking off at the top of the roots which facilitates its seeds Family: Asteraceae.

Centaurea (/ ˌ s ɛ n t ɔː ˈ r iː ə /) is a genus of between and species of herbaceous thistle-like flowering plants in the family s of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich.

In the western United States, yellow starthistles are an invasive species. The Necrotic Response to Nep1. Spotted knapweed and dandelion were much more sensitive to Nep1 than Arabidopsis was in these studies.

Spotted knapweed and dandelion had 25% and 75% leaf necrosis 24 h after treatment with 1 and 5 μg mL – 1 Nep1 (plus % [v/v] Silwet-L77), respectively. Necrotic spots on spotted knapweed and dandelion were uniformly spread and coalesced.

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Spotted knapweed, as the plant is more formally known, is a national menace, a weed of mass destruction. In Montana alone, it covers some million acres. Spotted knapweed is a biennial or short-lived perennial.

It is often found in open, disturbed areas where it grows in tufted clumps. One plant can give rise to 1 to 20 slender, upright stems 2–4 feet in height with most branching occurring in the upper half. Spotted knapweed is distinguished from the closely related species, diffuse knapweed (C. The lists of Colorado's Noxious Weeds are located in the below table.

To view more about a specific weed click on the name in blue text. If a plant name does not have a link this is because a plant plan or assessment has not been completed. SPOTTED KNAPWEED Produces chemicals that inhibit nearby plant growth, forming own habitat Highly competitive with native vegetation, reducing forage for livestock and large game an hybridize with Diffuse knapweed Native to Eurasia *ALWAYS read herbicide labels and follow instructions for use and use of a surfactant (aka sticker).

Print book: National government publication: EnglishView all editions and formats: Rating: (not yet rated) 0 with reviews - Be the first. Subjects: Diffuse knapweed -- Biological control -- United States. Spotted knapweed -- Biological control -- United States. United States.

More like this: Similar Items. spotted knapweed is unlikely (Sheley et al. Establishing competitive desirable plants is essential for successfully managing spotted knapweed. Spotted knapweed is a tap-rooted plant that can be controlled with cultivation to a depth of 7 inches, or hand removal.

Persistent pulling or digging can control spotted knapweed (Duncan et. In the book “Collapse,” Jared Diamond estimates the direct economic damage to Montana as $ Million, noting that they are “a huge pain in the neck to farmers, as they cannot be controlled by any single measure.” Controlling Spotted Knapweed with agricultural chemicals costs about 15.

Spotted knapweed has invaded rangeland throughout the western United States and Canada. This weed rapidly colonizes disturbed areas, but is also capable of invading well‐managed lands. Knapweed tends to dominate sites at the expense of community diversity or forage production.

It can occupy over 95 percent of the available plant community. Spotted Knapweed Root Weevil (Cyphocleonus achates) Introduced from Austria, Hungary, and Romania in the USA in This weevil prefers hot, dry sites with loose, well-drained, coarse soils.

Spotted Knapweed Flower Weevil (Larinus spp) Introduced from Greece and Romania and originally released in the USA in Its name is derived from the black margins of the flower bract tips which give the flower heads a spotted look.

Foliage A basal rosette of deeply lobed leaves is produced the first year. Rosette leaves are deeply lobed, petiolate, and approximately 8 in. (20 cm) long. Flowering stems are. The striking pink display of spotted knapweed, Centaurea stoebe ssp. micranthos, is still going strong in rangelands and old fields and along highways and railroad grades across the country.

Native to Europe, spotted knapweed was introduced accidentally to North America in the late 19th century, and has since become a problematic invasive weed.

The specimen in question was a knapweed root weevil — cyphocleonus achates. The weevil is a biological control for both diffuse and spotted knapweed, a noxious weed in Central Oregon.

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