f Jiminyweed, a dull green, bushy half shrub growing 1 or 2 (occa- 

 sionally 4) feet high, is also known as rayless-goldenrod and rosin- 

 weed, and sometimes is called rabbitbrush, apparently because of its 

 similarity to some species of rabbitbrush (Chrysdtharrwus spp.). 

 The Greek generic name Aplopappus means single or simple pappus, 

 and refers to the single series of unbranched, bristlelike hairs (pap- 

 pus) surmounting the "seed" (achene). The specific name hetero- 

 phyllus means dissimilar leaves and refers to the variation in the 

 leaves from nearly entire or untoothed to deeply lobed. 



This species ranges from Colorado to western Texas, Arizona, and 

 south into Mexico, growing on dry plains, mesas, and foothills from 

 the creosotebush (Comllea] belt up to the foothill woodland type. It 

 frequently occurs as the dominant plant over thousands of acres in 

 open savannah woodlands or on open grasslands. It spreads rapidly 

 by seeds during favorable years and often comes in abundantly on 

 overgrazed or depleted ranges. This species seldom grows on ranges 

 well stocked with perennial bunchgrasses, but when this perennial 

 cover is broken and replaced by annual grasses or other short-lived 

 plants, jimmyweed often rapidly invades the grasslands. It some- 

 times becomes one of the principal plants, even on areas covered by a 

 good stand of secondary grasses. It is a drought-resistant species, 

 largely because of its extensive root system, which penetrates to a 

 depth of 20 feet or more. 



Jimmyweed is poisonous to cattle, horses, and sheep and, on closely 

 grazed range, has caused much sickness and high mortality, especially 

 of cattle. It has long been under suspicion as the cause of "milk sick- 

 ness" or "alkali disease" of domestic animals in the Southwest, and is 

 also thought to be connected with the milk sickness of the human 

 beings who have used milk products from cows feeding upon this 

 plant. 1 Marsh, Roe, and Clawson found, through experimental work, 

 that cattle, horses, and sheep, when given sufficient quantities of ray- 

 less goldenrod (i. e., jimmyweed), develop all of the typical symp- 

 toms of alkali disease or milk sickness. * * * It has been snown 

 that the toxic substance may be excreted in milk, and that calves 

 and lambs may be poisoned in this manner. It is probable that 

 human cases of milk sickness arise from the consumption of milk or 

 butter from cows feeding on the rayless goldenrod. 



The outstanding symptoms 2 in poisoned animals are marked depres- 

 sion and weakness. The animals are inactive and often stand in a 

 humped posture and move with a stiff gait. The weakness is espe- 

 cially pronounced in the forelegs. In the more advanced stages of 

 the disease, the animal is unable to rise. Poisoning can usually be 

 detected by the trembling induced when the animal exercises; it 

 varies from a slight twitching to a violent shaking of the whole body, 

 and stockmen at times call the disease the trembles. Irritation of 

 both the intestines and kidneys is usually noticeable. Poisoned 

 animals should be kept as quiet as possible, since exercise aggravates 

 the trouble. Horses are the most easily poisoned by jimmyweed, and 



1 Marsh, C. D., and Roe, G. C. THE "ALKALI DISEASE" OF LIVESTOCK IN THE PECOS 

 VALLEY. TJ. S. Dept. Agr. Circ. 180. 8 pp.. illus. 1921. 



2 Marsh, C. D., Roe, G. C., and Clawson, A. B. RAYLESS GOLDENROD (APLOPAPPUS 

 HETEEOPHYLLUS) AS A POISONOUS PLANT. U. S. Dept. Agr. Bull. 1391, 24 pp., illus. 1926. 



