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Box Elder County Weed Control Department

Box Elder County Rush Skeleton Weed Project 2012


Figure 1. Plant in the budding stage, not yet flowering.

 Photo – T. Ziehl

Box Elder County Weed Dept is working cooperatively with the Northern Utah Soil Conservation District (NUSCD) to control a new invasive weed. The major infestation can be found between northern Howell Valley and Promontory Summit. The County Weed Department and the NUSCD is currently working on mapping and treating this noxious weed.


Figure 2. Died plant stage Promontory

Photo- B. Gilson

WEED: Rush skeletonweed Chondrilla juncea L.

FAMILY: Asteraceae (Sunflower family)




Brief Plant Description: (Paraphrased from references 2 and 8).

Roots: The plant is a deep‐rooted perennial, mostly 0.4 – 1.5 m tall, appearing somewhat rushlike.

Stems: The lowermost part of the branching stem bears distinctive large, spreading to slightly

descending, reddish hairs. The upper stem is hairless. Cut surfaces of stems and leaves release

milky sap.

Leaves: The early‐deciduous basal leaves are well‐developed, runcinate‐pinnatifid, five 13 x 3.5

cm, and strongly resemble dandelion leaves. The stem leaves are linear, 2 – 10 cm long and 1‐8

mm wide, and often also deciduous, the upper often reduced to scale‐like bracts.

Flowers: The flower heads are scattered along the branches, commonly with 9‐12 yellow, strapshaped

flowers per head. The involucre of bracts is 9 – 12 mm high and thinly clothed with

white, curly, intertangled hairs.

Fruit: The body of each, pale‐brown to almost black fruit is 3 – 3.5 mm long, with five broadly

rounded longitudinal ribs separated by grooves. The tip of the fruit body bears small pointed

bumps, then 5 small scales at the base of a long, slender beak, which bear that pappus of hairlike




A Couple Of Unwanted Guests In Box Elder County
(more information on links below Noxious Weeds Wanted Posters)


 Weed Complaints

USU Extension Weed Website

 Noxious Weed Identification Guide





 Bill Gilson
Box Elder County Weed Department