PAPILIONACSAE 



Apparently the plant, judging from, its condition where found, is 

 highly palatable. Its root system and its abundance in the site 

 where found suggest it as an excellent erosion control plant. It 

 should be mentioned also that it has been used as an ornamental, and 

 the seed of it is probably available from seed houses in the East. 

 It is possible, however, and even probable, that our southwestern 

 plant is either a different species or a remarkable drought resistant 

 strain. 



A stragalus spp. , Milk Vetches. This genus is a Dr. Jekyl and 

 Mr. Hyde. Several species are excellent forage and good or fair 

 erosion control plants, besides being legumes which build up the 

 nitrogen content of the soil. Many others are weeds, some of them 

 locos of the worst typo. In recent years much study has been given 

 to the element Selenium. First it was studied because of its pecu- 

 liar electrical properties, a study of which led to the invention 

 of the Selenium cell, the light-directed torpedo and similar devices. 

 The element was suggested for use as an insecticide and as such 

 proved very effective but it was soon learned that it was readily 

 absorbed by plants and that it rendered fruits and grains poisonous 

 to stock and to nan. For a time it was used as a depilatory but it 

 was soon learned that the hair disappeared from the crown of the 

 head as well as from the arm pits. But what has this to do with 

 Astragalus? Only this: Some species of Astragalus, and some other 

 plants as well, absorb selenium from soils containing it in the in- 

 organic form and upon decaying, return it to the soil in organic 

 form, in which condition it is readily absorbed by many plants which 

 are unable to absorb it in the inorganic form. Thus many plants 

 palatable to stock arc rendered poisonous. Fortunately not all soils 

 contain selenium in sufficient quantities to produce serious results. 

 It is highly probable that some of the poisoning ascribed to loco in 

 the past has really been duo to the selenium in the Astragali or to 

 that passed on by them to other plants. It can be seen by this that 

 the Astragali must be investigated thoroughly boforo they arc recom- 

 mended for use for erosion control or as forage. » 



At least two Astragali have recently come into prominence 

 not only as forage and erosion control plants but as crops. These 

 two, A. rubyi and A, mortoni, have not been given adequate trial in 

 our region to warrant conclusion regarding their value. Several 

 species Onobrychis, legumes similar to Astragalus, have been intro- 

 duced from Asia Minor and are being grown at the nursery at Tucson. 

 Before these can be planted on the range feeding experiments will 

 need to be conducted to determine their palatability, their relation 

 to the selenium of the soil and of first importance, whether they 

 are locos or not. 



Among the Astragali in the southwest which look promising for 

 forage and erosion control are A. 1 onchocarpus and A, nuttallianus . 



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