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Rush skeletonweed is a perennial, 1
to 4 feet tall. Starting at the stem base for 4 to 6 inches,
stems usually have downwardly bent coarse hairs; smooth stems
above. Leaves form in a basal rosette, sharply toothed, and
wither as the flower stem develops. Leaves of the stem are
inconspicuous, narrow and entire. Flowering heads are
scattered on branches, approximately 3/4 inch in diameter, with 7
to 15 yellow, strp-shaped flowers. Seeds are pale brown to
nearly black, about 1/8 inch long. Body of seed is
several-ribbed, smooth below with tiny scaly projections above,
terminated by a long beak with numerous soft white bristles.
Rush skeletonweed is an
introduced Eurasian species which presently infests several
million acres in Idaho, Oregon, Washingon and California. It
generally inhabits well-drained, light-textured soils along
roadsides, in rangelands, grain fields and pastures. Soil
disturbance aids establishment. The extensive and deep root
system makes skeletonweed difficult to control. Cut surfaces
of the leaves and stems exude a milky lated. Flowering and
seed production occur from mid-July through frost.
Chemical control
Herbicide: Transline or
Stinger (clopyralid)
Description: Apply o.66 to 1
pt/A Transline or
Stinger
Timing: Apply to rosettes,
fall or spring
Herbicide: Tordon (picloram)
Description: Apply 1 lb ae/A
picloram
Timing: Apply to rosettes,
fall or spring
Herbicide: 2, 4-D
Description: Apply 2 lb ae/A
2,4-D; additional treatment will be necessary
Timing: Apply to rosettes in
spring
Herbicide: MCPA
Description: Apply 2 lb ae/A
MCPA; additional treatment will be necessary
Timing: Apply to rosettes in
spring
Biological control
Insect: Rust (Puccinia
chondrillina)
Description: Rust infects the
rosette in the fall and spring, causing brown pustules to erupt
through the leaf and stem surfaces. Collect P.
chondrilling July 1 to August 15.
Redistribution: June 1 to
August 15
Insect: Gall midge (ystiphora
schmidti)
Description: Larval feeding
stresses the plant and can reduce flowering. Collect stems
with galls.
Redistribution: July 1 to
August 1
Insect: Gall mite (Eriophyes
chondrillae)
Description: Mites feed on
flower buds or stem tips. High mite populations stunt and
deform plants and can stop seed production. Collect green
galls with some yellow to rust color.
Redistribution: July 1 to
August 15
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