Latin Name: Chondrilla juncea
Physical Description: Perennial herb from a taproot. Its stems are rush-like, branched, contain a milky juice and can grow up to 1m tall. The upper stems are highly branched and nearly hairless, with few to no leaves. The lower stems have dense, bristly downward pointing hairs. The leaves have sharply cleft margins with lobes pointing backwards, and wither at flowering. The flower heads are yellow and resemble dandelion flowers. They grow on the tips of the stem either alone or in small clusters.
Habitat: It prefers coarse-textured, well-drained soils which can be calcareous or mildly acidic. It requires a relatively hot, dry summer without an extended summer drought. It can often be found in dry grasslands, croplands, semi-arid pastures and rangelands, waste places and along roadsides. It also grows well along riverbanks, dry river beds and sandy areas.
Impacts: It is a highly competitive and aggressive noxious weed that outcompetes native and/or desired plants. It can reduce available forage for wildlife and livestock and reduce crop yields. It can also foul harvesting machinery.
Reproduction: It reproduces by seed and vegetatively from root buds. Individual plants can produce 1,500 to 20,000 parachute-like seeds that travel easily with wind, water, animals, and humans. Buds on the upper root or lateral roots can produce daughter rosettes and multiple daughter rosettes can develop from one root crown. Roots are easily fragmented and pieces as small as 1 cm can produce new rosettes from a depth of 1m.
Mechanical: Small infestations can be successfully hand pulled when the soil is moist and plants are immature if care is taken to remove the entire root system. Hand pulling will need to be repeated as any severed root will re-sprout. Regular mowing is partially effective as it can reduce aerial and root biomass and reduce seed production. However, mowing is not effective at eliminating rosettes as these are close to the ground. Cutting stems close to the surface is not recommended as the plant will produce multiple stemmed plants. Mechanical cultivation is not recommended as it will distribute severed pieces of root and increase the infestation.
Chemical: Several herbicides with the following active ingredients can control Rush skeletonweed: 2,4-D, aminopyralid, aminopyralid + 2,4-D. Clopyralid, Cloypyralid +2,4-D, Dicamba, Picloram, Glyphosate, and Imazapyr. For available products, contact your local agri-supply store. Prior to any herbicide application, read and follow the label instructions.
Biological: Aceria chondrilla is a gall forming mite that has been released into and found established in the Interior cedar hemlock and Interior Douglas-fir biogeoclimatic zones. It is also freely dispersing itself within these zones. The mite’s dispersal in B.C. is likely restricted by the limited distribution of the host plant.