United States Department of Agriculture

Field Guide for Managing

Rush Skeletonweed

in the Southwest

Forest 

Service

Southwestern

Region TP-R3-16-22 Revised June 2017
Cover Photos

Top left: Utah State University Archive, Utah State University, Bugwood.org

Top right: Richard Old, XID Services, Inc., Bugwood.org

Lower center: Utah State University Archive, Utah State University, Bugwood.org

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1 

Rush skeletonweed (Chondrilla juncea L.)

Sunflower family (Asteraceae), Lactuceae tribe (Cichorieae)

Rush skeletonweed is an invasive plant in the Southwest

that has been listed as a noxious weed in Arizona. This

field guide serves as the U.S. Forest Service’s

recommendations for management of rush skeletonweed in

forests, woodlands, and rangelands associated with its

Southwestern Region. The Southwestern Region covers 

Arizonaand New Mexico, which together have 11 national

forests. The Region also administers 4 national grasslands

located in northeastern New Mexico, western Oklahoma, 

and the Texas panhandle.

Description

Rush skeletonweed (synonyms: skeletonweed, hogbite,

gum succory, devil’s grass, naked weed) is a wiry-looking

perennial that was introduced from Eurasia. Given 

favorable conditions, the species can spread rapidly and 

form dense infestations. Thus far, three distinct genotypes 

have been identified with each genotype differing slightly 

in the appearance of the rosette leaves and branching. In 

the rosette stage, rush skeletonweed resembles common 

dandelion (Taraxacum officinale) or chicory (Cichorium 

intybus L.). After bolting, rush skeletonweed can be 

distinguished by its brown, downward-pointing hairs near 

the base of the flowering stem.

Growth Characteristics

• Long-lived perennial herbaceous plant; mimics a 

biennial (overwinters as a rosette).

• Deep and stout taproot; rapidly grows overwinter to 

a depth of 3 to 7 feet.

• Rosette base with 2 to 5 inch hairless reddish-brown 

leaves with purplish incised margins and lobes

pointing backward toward the leaf base; lobes are so

deep the leaf looks nearly pinnate.

• Produces bright green or yellowish, wiry, erectly 

branching flowering stems in spring; stem has few 

narrow, linear leaves with entire margins and brown,

downward-pointing hairs at its base. Flowering stem

is persistent and becomes increasingly tough as it

matures; 16 to 48 inches tall.

• Exudes a white milky substance from cut, broken, or 

damaged stem, leaf, and root surfaces.

• Small, bright yellow flowers from May until first

frost; flowers are located on the end of the branch 

(terminal) or between the branch and stem (axillary).

The flowers may be directly attached to the branch 

(sessile) or be on short stalks (pedicelled); flowers

may also be found in clusters of 2 to 5. Instead of 

the disk and ray flowers common to other species in

the Asteraceae family, rush skeletonweed has only

one type of flower (ligulate). Heads have 9 to 12

strap-shaped flowers; each flower has 5 fused petals

that have a toothed appearance at the tip.

• Reproduces mainly vegetatively via adventitious 

buds near the top of the taproot; lateral roots near 

surface can become rhizome like and also have root 

buds; dense patches of cloned plants may form in

response to damage. 

• Seed is asexually produced (15,000 to 20,000 seeds 

per plant). Seeds are oblong, ribbed achenes with a 

pappus of numerous soft bristles. Depending on soil 

conditions, seeds may remain viable from 6 months 

to more than 8 years. Seed quickly germinates in 

response to available moisture; seedling mortality 

rate is high should extremely dry conditions occur 

immediately after establishment.

Ecology

Impacts/Threats

Rapid spread of rush skeletonweed is potentially high once 

it is introduced to an area with favorable growth 

conditions; it is difficult to eradicate once established. The 

weed diminishes preferred rangeland forage and reduces 

plant and animal diversity. It also causes lost production in

wheat fields, and its persistent flower stems are so tough 

they can hamper harvest machinery. 
2

Site/Distribution

Rush skeletonweed adapts to a wide range of climate

zones and environmental conditions. However, it is limited 

by the amount of calciumand phosphorous available in the 

soil. Generally, rush skeletonweed prefers well-drained 

sand or gravel and does not fare well in waterlogged or 

heavy clay soils. It also favors areas with 10 to 40 inches 

of precipitation, preferably with moisture available at the 

onset of the cool season and in the spring. It can invade 

roadsides and other transportation corridors, rotational

pastures, croplands (especially grain fields), waste areas,

and rangelands.

The species is now widespread in western States including 

Washington, Oregon, Idaho, Montana, and California. An 

isolated, yet expanding population has been found in the 

Grand Canyon National Park in Arizona.

Spread

Although rush skeletonweed produces wind-dispersed

seed, it spreads mainly through vegetative propagation that

arises from adventitious buds. Root fragments as little as

about one-half inch in length can produce new plants even

if buried in soil to a depth of 3 feet. Seed or root fragments 

may be introduced into new areas via transportation 

corridors such as roadways and train tracks. Rush 

skeletonweed may also spread through transported hay that 

is not certified to be weed-free or by attachment of 

propagules that adhere to the undercarriages of off-road 

vehicles and road maintenance equipment. The most rapid 

spread appears to occur at mid-elevation areas.

Invasive Features

While rush skeletonweed is capable of spreading rapidly, it 

does not typically invade stands of native vegetation in

good condition. Open plant communities, drought, and soil 

disturbance from human or animal activities can increase 

the likelihood for invasion. The competiveness of rush

skeletonweed is believed to be related to its ability to 

reproduce vegetatively in response to damage such as 

severed roots, stems cut near the base, and fire. Once 

established, grasses are unlikely to outcompete rush 

skeletonweed for water and nutrients.

Management

Prevention along with early detection are the most costeffective management actions against this invasive plant.

An integrated management strategy that combines several 

control methods should be implemented to contain, 

reduce, or eradicate populations of mature rush 

skeletonweed. As with other perennial weeds that 

primarily reproduce vegetatively, treatment should involve 

attacking the extensive root system. 

The following action measures should be considered when 

planning an overall management approach:

• Maintain healthy plant communities and the 

presence of ground litter to prevent or limit rush

skeletonweed infestations. This may involve 

improving grazing management practices to prevent 

excessive grazing and the reseeding of disturbed 

areas with desirable forbs and grasses.

• Use certified weed-free seed and hay; use pellets for 

horses used in backcountry areas.

• Eradicate new populations of rush skeletonweed as 

early as possible. 

• Detect, report, and map large infestations. Keep 

annual records of reported infestations.

• Combine cultural, biological, and chemical methods 

for effective rush skeletonweed control.

• Implement a monitoring and follow-up treatment 

plan for missed plants and seedlings.

Table 1 summarizes management options for controlling 

rush skeletonweed under various situations. Further details 

on these management options follow the table. Choice of 

individual control method(s) for rush skeletonweed 

depends on the extent and density of infestation, current 

land use, and site conditions (weather, accessibility, 

terrain, other flora and fauna present, etc.). The specific 

biotype of rush skeletonweed present should also be 

considered as each one may respond uniquely to different

treatments. Other considerations include treatment

effectiveness, overall cost, and number of years needed to

achieve control. More than one control method will likely

be needed for a particular site. 
3 

Table 1. Management options*

Site Physical Control Cultural Control Biological Control Chemical Control

Roadsides,

fence lines,

or non-crop 

areas

Cultivation may increase

root spread and is not

recommended. 

Repeated mowing is a

suppression option along

roadways although this will 

not kill the weed.

Use seed, mulch, and fill 

materials certified to be weedfree. 

Avoid driving vehicles and

equipment through infested

areas; wash if travel through

these areas is unavoidable. 

Educate road crews and others 

to identify and report

infestations. 

Several classic biocontrol agents are 

available for use alone or in 

combination with herbicide control

(see table 2 for recommendations). 

Use truck or tractormounted spraying 

equipment to broadcast 

treat. Wash underneath 

vehicle after 

application to prevent 

spread. 

Rangelands, 

pastures, or

riparian 

corridors 

Mowing, tilling, and 

burning are not 

recommended as these

practices often increase

weed density.

Where feasible, consider 

planting competitive

legumes, such as alfalfa and

clover. 

Use seed and forage hay

certified to be weed-free; use 

pellets for horses in 

backcountry areas.

Always evaluate the need to 

reseed. While grasses will not

outcompete established stands 

of rush skeletonweed, the

presence of native vegetation 

in good condition may deter

further invasion. 

Several classic biocontrol agents are 

available for use alone or in 

combination with herbicide control 

(see table 2 for recommendations). 

Moderate, continuous grazing by 

sheep and goats can reduce rosette

formation and seed production. 

If possible, avoid grazing when rush 

skeletonweed is in flower or after 

seed has set. Closely manage grazing 

to prevent overuse.

In areas difficult to 

access, an ATVmounted sprayer or 

backpack unit may be 

the most practical

application methods. 

Wash underneath 

vehicle after

application to prevent

spread. 

Wilderness, 

other natural

areas, and/or

small

infestations 

Hand removal by pulling or 

digging 2 to 3 times per

year for several years may

aid in control. Pull when

soil is moist; remove all 

root material; wear gloves 

for pulling. These methods 

are most effective on very 

small populations of newly

established plants.

Use seed and forage hay 

certified to be weed-free; use 

pellets for horses in 

backcountry areas.

Post signs warning visitors to

remove seeds after passing 

through infested areas; 

discourage travel through 

infested areas if possible. 

Same as above. Use backpack or handheld sprayers. 

Broadcast spraying 

with ground methods 

may be used on thicker 

stands if allowed.

Remove seed from 

clothing to prevent 

spread. 

* Choice of a particular management option must be in compliance with existing regulations for the land resource. 

Physical Control

New rush skeletonweed plants (younger than 5 weeks) 

have poorly developed roots and are easily killed when

uprooted. With the exception of plants less than 5 weeks 

old, most rush skeletonweed will re-sprout from severed

roots in previously weeded areas; therefore, removal of 

young plants as early as possible is critical.

Manual Methods

Hand removal –Hand pulling, hoeing, or digging can 

be effective for smaller, isolated infestations of rush 

skeletonweed if repeated 2 to 3 times per year over a

number of years (3 to 10). Removal is easier when the soil 

is moist and plants are beginning to bolt (but before seed 

set). While it is very important to pull up all parts of the 

plant (especially roots), it is unlikely that all root fragments 

will be removed.

It is recommended that treated areas be continually 

monitored (about every 2 weeks) to find and remove newly 

emerged weeds. Wear gloves and properly dispose of debris 

by burning in a very hot fire or by bagging and burying in a 

landfill to prevent spread.
4

Mechanical Methods

Most mechanical control methods forrush skeletonweed 

have limited effectiveness, especially in areas where the 

weed has become well established. Cultivation practices 

that do not eliminate the root system may lead to further 

spread and an increase in weed density. However, 

mechanical control may be helpful as part of an integrated

management plan.

Tillage – Cultivation or tillage is not recommended for 

rush skeletonweed. Shallow disking should especially be 

avoided since deeply growing severed roots will quickly 

regenerate new stems and plants.

Mowing – Mowing is generally not recommended. Since

rush skeletonweed has such a deep and extensive root 

system, mowing does not significantly impact nutrient 

reserves and may contribute to an increase in population

density. However, repeated mowing before seed set is

sometimes used along roadways for suppression of top 

growth.Consider repeated mowing along roadsides in

combination with herbicides and the use of biocontrol

agents. Rust and mites are recommended as biocontrol

agents for use in roadside settings (see the “Integrated

Control Methods” segment below for further information).

If using mowers to manage rush skeletonweed, the 

equipment should be cleaned after use to prevent 

movement of seed and root fragments into un-infested 

areas. 

Prescribed Fire

Burning is not recommended. New plants from roots are

quickly produced after fire, which often leads to increased 

dominance by rush skeletonweed. However, fire may be 

used to destroy debris.

Cultural Control

Prevention, early detection, and plant removal are critical

for preventing rush skeletonweed establishment. Land

managers, road crews, and the local public should be

educated on identification of rush skeletonweed to help 

report all suspected infestations. Seed and materials used 

for mulch, forage, or fill should be certified to be weedfree; pellets may be used for horses in backcountry areas.

Biological Control

Grazing

Rush skeletonweed provides some grazing value in the

rosette stage, but it is avoided by most animals after it has

reached the bolting stage. Livestock (including cattle, 

horses, sheep, and goats) and some wildlife will graze rush

skeletonweed until the stem becomes tough and woody

(lignified); goats will graze later into the season than other 

livestock. Moderate, continuous grazing by sheep or goats 

has been found to prevent the weed from sending up a

flowering stem during the summer, thus reducing seed 

production. Grazing should be discouraged wherever

plants with flowers are present or when seed has already

set. For information on combining grazing with other 

control methods, see the “Integrated Control Methods” 

segment below.

Classical Biological Control

Four classical biocontrol agents have been approved for rush 

skeletonweed control in North America: a gall-forming mite, 

a midge, a rust fungus, and a root-feeding moth (table 2). In 

Australia, biocontrol agents are widely used on rush 

skeletonweed where the weed reportedly has become less 

of a problem due to this type of management. Biocontrol 

agents will not eradicate rush skeletonweed, but they will 

reduce seed production and stunt the weed’s competitive 

growth. In combination with herbicide application, 

biocontrol agents have been used successfully in rangeland 

settings to control rush skeletonweed (see the “Integrated

Control Methods” segment below for further information).

Generally, it is recommended that the rust be released in the 

spring or fall; mites in the summer; and the midge in the 

spring. It is very important to consult persons familiar with 

use of these agents before making a release. Following the 

release of any biocontrol agent, patience and limited 

interference are recommended.

Organisms (insects, pathogens, etc.) used as biocontrol 

agents in southwestern States should be adaptable to arid 

environments and local conditions. Public, tribal, and 

private land managers may obtain biocontrol agents for 

release directly from local offices of the USDA Animal

and Plant Health Inspection Service (APHIS) when these
5 

Table 2. Classical biocontrol agents approved for rush skeletonweed

Species Type of Agent Site of Attack Impacts Use/Considerations for Release

Aceria

chondrillae

gall-forming mite shoots; axillary 

and terminal buds 

Highly effective for reducing 

seed production and killing

young plants.

More effective on certain rush skeleton 

biotypes; dependent on the presence of 

rosettes to overwinter. 

Readily available; an APHIS permit is 

required prior to transport across State lines. 

Bradyrrhoa 

gilveolella

root-feeding

moth

stem base and

root; buds near 

root crown

Reduces plant vigor and

reproduction; kills young 

plants and makes larger 

plants susceptible to fungi.

Limited establishment in Pacific Northwest.

Lab-reared in Idaho; an APHIS permit is 

required prior to transport across State 

lines. 

Cystiphora

schmidti

gall-forming

midge 

stems and leaves Causes leaf damage when

exiting from galls.

Consider using this and the following two

agents together for greater impact.

Readily available; an APHIS permit is 

required prior to transport across State lines. 

Puccinia

chondrillina

rust fungus seedlings; whole 

plant 

Kills seedlings; severely 

stresses host plant causing

stunting and desiccation. 

Appears to favor areas with higher overnight 

humidity; has done well in California. 

Readily available; an APHIS permit is 

required prior to transport across State lines. 

agents are available. Other sources for biocontrol agents 

include locally developed insectaries or private 

companies. 

A permit must be obtained from APHIS before biocontrol 

agents can be transported across State lines. Regulations 

and permit applications (PPQ 526 permit forms) 

pertaining to interstate shipment of biocontrol agents can 

be found at https://www.aphis.usda.gov/aphis/ourfocus/ 

planthealth/import-information/permits/regulatedorganism-and-soil-permits/sa_apply/ct_plantpest

_howtoapply. Although biocontrol agents may be 

collected and released internally in a given State without 

an APHIS permit, the State’s department of agriculture or 

agricultural extension service should be consulted for any 

regulations relating to movement of these agents within 

the State.

Chemical Control

All herbicides recommended in table 3 may be considered 

for rush skeletonweed control. Selective herbicides

include picloram, aminopyralid, or aminocyclopyrachlor

in combination with chlorsulfuron or metsulfuron. Adding

2,4-D amine with these herbicides when spraying in the

spring has provided enhanced control. When mixing the

herbicide solution, add an effective surfactant as 

suggested on the label. Rush skeletonweed has a rubbery 

stem surface with few leaves, and herbicide uptake can be 

improved by including a methylated seed oil surfactant 

such as Dyne-Amic®.

Each herbicide product will have different requirements 

and restrictions according to the label. Read and 

understand prior to any application. To prevent resistance

in rush skeletonweed as a result of repeated treatments,

the label should be consulted for guidelines on rotating 

herbicide active ingredients. Consult the registrant if you 

have questions or need further detail. 

Herbicide Application

Rush skeletonweed is difficult to control with herbicides, 

especially after the main stem has bolted and flowering 

occurs. Spraying should be done in either the spring or

more effectively in the fall when the weed is in the rosette 

stage. The herbicide application is timed to prevent the 

formation of a flowering stem. It is important that an 
6 

Table 3. Herbicide recommendations

Common

Chemical

Name (active 

ingredient)

Product

Example1

Broadcast 

Treatment 

(rate per 

acre)

Spot 

Treatment 

(spray 

solution)2

Time of

Application Remarks

Picloram3 Tordon 22K 1–2 quarts; add 

surfactant as 

recommended on 

label. 

1–3% At rosette stage

in fall or early

spring.

Spray mature

plants after first

frost in the fall. 

Restricted use herbicide that is selective although

persistent. 

May be used in combination with 2,4-D4. At lower 

rate, may also be used in combination with biocontrol

agents. Wait 2 months to reseed perennial grasses.

Aminopyralid Milestone 5–7 ounces; add 

surfactant as 

recommended on 

label. 

5–10% Same as above. Residual from late fall treatment of mature plants can

be effective in controlling seedling emergence in the

spring.

May be used in combination with 2,4-D4

. Labeled 

for use up to water’s edge. No grazing restrictions. 

2,4-D amine4 multiple

products

available 

1 gallon; add 

surfactant as 

recommended on 

label. 

3% At rosette stage

in spring (before 

bolt). 

2,4-D4 reduces aboveground growth but does not 

translocate into the extensive root system; thus, plant 

kill is poor. Combining this herbicide with another 

herbicide may increase efficacy. 

Aminocyclopyrachlor

+ chlorsulfuron

Perspective 4.75–8 ounces; 

add surfactant as 

recommended on 

label. 

Add 5–9 grams

of dry flowable

powder for 

each gallon of

water.

Most effective on 

rosettes in late fall

after frost.

A selective blend of active ingredients labeled for 

non-crop use (includes natural areas such as wildlife

management areas, wildlife habitats, recreation areas,

campgrounds, trailheads, and trails). Persistent; 

selective for broad-leaved plants; may cause 

temporary injury to some grass species. 

May be used on public, private, and tribal lands as part

of an early detection and rapid response (EDRR) in

treating infestations of invasive weed species. 

Aminocyclopyrachlor

+ metsulfuron methyl

Streamline 4.75–9.5 ounces; 

add surfactant as 

recommended on 

label. 

Same as above. Same as above. Same as above. May cause temporary injury in some 

grass species.

Imazapyr Arsenal 3–4 pints 1% Any time when 

plants are growing 

or in the fall after

frost.

Nonselective herbicide used primarily for follow-up

spot treatment. 

In addition to spray drift, nontarget plants may also be 

killed or injured by imazapyr through runoff, residue 

movement in soil, or root exudates from treated plants.

Use direct spray or a wipe method when desirable

plants are present. 

1 Trade names for products are provided for example purposes only, and other products with the same active ingredient(s) may be available. Individual product 

labels should be examined for specific information and appropriate use with rush skeletonweed.

2 Spray solution is the herbicide/water ratio in a spray mix that may be used for spot treatment with backpack or hand-held sprayers. The amount of product 

applied during an annual growing season must not exceed the maximum application rate per acre as specified by the product label – refer to the product 

label for the site type and application.

3 Restricted-use pesticide – A certified applicator’s license is required for purchase and use of these pesticides.

4 2,4-D is a restricted use pesticide in New Mexico only.
7 

aggressive plan for re-treatment be followed to achieve 

long-term success. For example, spraying in the rosette 

stage early in the spring and again later in the fall 

(preferably after the first frost) has been shown to be 

effective in controlling rush skeletonweed. However,

spray treatments often need to be repeated for 3 years.

Herbicides may be applied by wipes, backpack or handheld sprayers, ATV or UTV sprayers, or conventional 

boom sprayers that are pulled or attached to a tractor or 

truck. In certain situations where rush skeletonweed is 

dense and widespread, aerial herbicide application by

fixed-wing aircraft or helicopter should be considered. 

Any equipment used to spray herbicide should be 

calibrated.

Integrated Control Methods

Biocontrol agents

For heavily infested areas or areas difficult to treat with 

conventional methods, consider combining classical 

biocontrol agents with other control methods to reduce 

further spread. An appropriate biocontrol agent for rush 

skeletonweed may be used in conjunction with herbicide 

applications timed to prevent formation of flowering 

stems. Areas larger than an acre can be sprayed in the 

spring or fall, which is then followed by release of the 

biocontrol agent during the following growing season. 

This approach has been successful in providing long-term 

control. Other strategies integrated with biocontrol agents

that may be considered for management of large 

infestations of rush skeletonweed include: 

• Mowing–biocontrol–herbicide treatment for

roadsides – For roadsides, mow repeatedly at 2 to 

3-week intervals during the growing season. 

Consider releasing or bolstering biocontrol 

populations of rust and mites. In the fall or spring, 

apply herbicide to rush skeletonweed growing in the 

rosette stage. Typically, it is necessary to visit and 

re-treat areas later in the season which should be 

repeated for 1 or 2 years. 

• Grazing–herbicide–biocontrol treatment for

rangeland – For large infestations in a rangeland

setting, use a moderate, continuous grazing approach

to maintain plants in rosette form, thus reducing seed

production. Apply herbicide to rosettes in the fall

that are effective in killing below ground portions. 

Introduce biocontrol agents or reinforce existing 

biocontrol populations in the season recommended

for release of each particular agent. Midge agents

are typically released in spring; mites in summer. 

Biocontrol agents can attack the plants that remain

following herbicide application and further

contribute to control.

Management Strategies

Preventive techniques should be practiced where suitable.

Planning and treatments to control previously established 

patches of rush skeletonweed should be designed to meet 

the needs of each specific site. High priority should be 

given to eradicating small, isolated patches or satellite 

populations of rush skeletonweed on otherwise healthy 

sites, followed by weeds found along transportation 

corridors such as along railways or roadsides. For 

widespread infestations of rush skeletonweed, containment 

may be a more realistic goal than eradication.

When developing a strategy to control rush skeletonweed, 

consider complementary restoration activities (such as 

reseeding with native perennial plants) as a way to further 

limit rush skeletonweed populations. Where feasible, 

planting legumes such as clover and alfalfa has been 

shown to be an effective way to provide competition and 

reduce the density of rush skeletonweed.

Previously treated areas should always be monitored to 

detect recovering rush skeletonweed. Look for isolated,

newly emerged rush skeletonweed plants in the spring and 

treat with herbicide. Monitor treated plants after 2 to 4 

weeks to observe how plants have responded to treatment. 

If necessary, apply herbicide to plants that did not respond

to the first treatment. Evaluate all treated areas in the fall 

and respray new growth if necessary.

In most cases, several consecutive years of field treatments 

will be necessary to eliminate or substantially reduce rush 

skeletonweed. Since it is ordinarily useless to treat an area 

only one time without retreatment, sufficient resources must 

be allocated for the area where control is attempted. After 
8 

initial treatment, it is important that resources are also 

available to respray or retreat the treated area successfully.

Adaptive Management

A persistent, coordinated commitment over many years is 

required for successful control of rush skeletonweed. 

Therefore, realistic goals and objectives should be

established to prevent rush skeletonweed from spreading 

extensively throughout a given landscape. To improve longterm success, consider using an adaptive management 

approach with the overall goal of restoring desirable plant 

communities. The stepwise process for adaptive management 

involves: 

1. Assessment of the overall weed problem,

2. Establishing management goals and objectives,

3. Implementation of control strategies and measures, 

4. Monitoring the effectiveness of management actions,

5. Evaluating actual outcomes in relation to expected

results, and

6. Adjusting practices as necessary.

Steps of this process should be repeated in sequence as part

of a continuous learning cycle that improves management

planning and strategy by learning from the outcomes of 

previous management actions. In general, an adaptive 

management approach is considered to be successful if: 

1. Stakeholders are actively involved and remain 

committed to the process, 

2. Monitoring and assessment are used to adjust and

improve management decisions, and

3. Management goals and/or objectives for the 

resource are being achieved.

References and Further

Information

California Dept. of Food andAgriculture. Encycloweedia 

Datasheets: Rush Skeletonweed. Available at

http://www.cdfa.ca.gov/phpps/ipc/weedinfo/

chondrilla-juncea.htm (accessedOct. 2011).

DiTomaso, J.M. and E.A. Healy. 2007. Weeds of California 

and Other Western States. University of California

Agriculture and Natural Resource Publication 3488. 

Pp. 264–267. Available at http://books.google.com/

books (accessed October 2011).

Gaskin, J.F. 2009. Rush Skeletonweed (Chondrilla Juncea) 

Management Plan for the Western United States. In 

Rachel, W., Schwarzlander, M., Gaskin, J.F., 

Crabtree, C., eds. 1st ed. Forest Health Technology 

Enterprise Team. pp. 117.

Heap, J.W. 1993. Control of Rush Skeletonweed 

(Chondrilla juncea) with Herbicides. Journal of

Weed Technology. 7(4): 954–959 (accessed via 

JSTOR October 2011).

Horner, T.A. 2002. Field Release of Bradyrrhoa gilveolella

(Lepidoptera: Pyralidae), for Biological Control of 

Rush Skletonweed, Chondrilla juncea (Asteraceae).

Available athttp://www.aphis.usda.gov/plant_health/

plant_pest_info/weeds/downloads/envirodocs/

bradyrrhoa.pdf (accessed Oct. 2011)

Laws, C.S. 2004. Plant Assessment Form for Chondrilla 

juncea for Arizona Wildland Invasive PlantWorking

Group. Available at http://sbsc.wr.usgs.gov/research/ 

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Suggested Web Sites

For information on invasive species:

National Invasive Species Information Center

http://www.invasivespeciesinfo.gov/

Invasive.org

https://www.invasive.org/species.cfm

For information about calibrating spray equipment: NMSU 

Cooperative Extension Service Guide A-613, Sprayer 

Calibration. Available at

http://aces.nmsu.edu/pubs/_a/A-613.pdf

Herbicide labels online:

http://www.cdms.net/
For more information or

other field guides, contact:

USDA Forest Service 

Southwestern Region

Forest Health

333 Broadway Blvd., SE 

Albuquerque, NM 87102

Or visit the Southwestern Region’s 

website for invasive species:

http://www.fs.usda.gov/goto/r3/invasivespecies

The use of trade or firm names in this publication is for reader 

information only and does not imply endorsement of any 

product or service by the U.S. Department of Agriculture. 

Recommendations made here for 

pesticide use are not obligatory, 

nor do they imply that discussed 

uses have been registered. All 

uses of pesticides must be 

registered by appropriate State 

and/or Federal agencies before 

they can be applied. 

CAUTION: Pesticides can be

injurious to humans, domestic 

animals, desirable plants, and fish or other wildlife—if they are 

not handled or applied properly. Use all pesticides carefully 

and lawfully. Follow recommended practices for the disposal 

of surplus pesticides and pesticide containers.