352 MANUAL OF POISONOUS PLANTS 



The North Dakota Station has published the results of further experiments 

 on the subject of feeding millet. Two tests were made. In the first trial two 

 geldings in good health were fed hay and grain for about two weeks. Millet 

 was then substituted for hay for about ten days. These experiments confirmed 

 those made previously. 



Ladd has isolated a glucoside from the aqueous extract of millet hay, which, 

 when fed in small quantities, gave the characteristic symptoms. 



From the experiments made by Dr. Hinebauch and others, it would appear 

 that feeding millets alone as coarse fodder is injurious to horses. It produces 

 an increased action of the kidneys and causes lameness and swelling of the 

 joints. It causes an infusion of blood into the joints and destroys the texture 

 of the bone, rendering it soft and less tenacious, so that the ligaments and 

 muscles are easily torn loose. 



5. Cenchrus, L. Sand Bur 



Annual or perennial grasses ; flat leaves ; spikelets surrounded by a spiny in- 

 volucre which becomes coriaceous and forms a deciduous, hard, rigid bur which 

 falls away at maturity; glumes 4, the 2nd and 3rd membranaceous, the 4th 

 hard ; the palea enclosing the perfect flower ; stamens 3 ; styles united below. 



Species about 12 in tropical and warmer temperate regions. One widely 

 distributed from Maine to New York, Florida, Texas, California and the 

 Dakotas. 



Cenchrus tribuloides, L. Sand Bur 



An annual with erect culms a foot or more high ; flat leaves about 6 inches 

 long; burrs of the involucre with strong, barbed spines; 2-flowered. 



Distribution. Common in sandy fields and waste places; a weed along rail- 

 roads and in sandy soil. 



Injurious Properties. This plant frequently inflicts mechanical injuries. 

 entering the flesh and thus causing serious inflammation. This applies to man 

 as well as to lower animals. 



Aristida, L. Triple Awned Grass 



Perennial or annual grasses ; narrow, often involute leaves ; spikelets nar- 

 row, 1 -flowered; outer glumes unequal, often bristle pointed; flowering glume 

 tipped with 3 awns; palet small, 2-ncrved ; stamens 3; styles distinct: grain free, 

 linear, enclosed in the scale; callus variable, often sharp-pointed and rigid. 

 About 100 species in warmer regions of both hemisplieres but of very little 

 economic value, the majority being found in dry sterile soil; several species, 

 like the Purple Aristida, however, are common in dry soils of the West. The 

 latter is of little value for forage purposes. The awns of Aristida hygrometrica 

 of Queensland bore into the skin of animals and occasionally reach the intes- 

 tines, thus causing death. 



None of our species produces serious trouble except, possibly, the Long- 

 awned Poverty Grass. 



Aristida tuberculosa, Nutt. Long Awned Poverty Grass 



A rigid, much-branched annual, 12-18 inches high, with nearly simple 

 panicles, 4-7 inches long; branches erect, rather distant, the lower in pairs, one 

 short and few-flowered, the other elongated and many-flowered ; empty glumes 



