CROSSOSOMATACEAE 



Crossosoma bigeloyii, is a low, slender, much-branched shrub 

 with fa sic led grayish leaves and white flowers with clawed petals. 

 It is confined to the foothills and lower slopes and canyons of our 

 extreme southwestern ranges. This shrub is showy while in flower 

 but has little promise as an economic plant except possibly as an 

 ornamental, 



ROSACEAE 



Cowania s tans burl ana , Cliff Hose, is comparable to Cercocarpus 

 and Fallugia in erosion control value. It often forms almost pure 

 stands on rocky dry slopes. This species has high forage value and 

 grows through a wide range of altitudes. It ranges throughout the 

 southern portion of the Rocky Mountains from, central Colorado and 

 Utah. Like Cercocarpus and Fallugia, this species can best be pro- 

 pagated ir. the nursery and. plants transferred to the field. It 

 grows well in the nursery. 



* Cercocarpus raontanus, the common Mountain Mahogany, Is one of 

 the most common shrubs in the mountains of our region. It extends 

 also far north and south of our territory. Perhaps what is discus- 

 sed hers represents more than one species, variety or strain. For 

 example, the form so common in the mountains between Superior and 

 Miami, Arizona appears different superficially to that in the moun- 

 tains about Prose ott. The different forms, however, have much the 

 same habit and can well be considered together. This is one of the 

 best shrubs in our mountains for both erosion control and for forage. 

 It usually forms almost pure stands covering large areas and its 

 roots quite effectively check erosion. In many places grazing has 

 been severe, resulting in misshapen twigs -and bushes but these always 

 put out masses of leaves and survive the ordeal. 



The seeds of this shrub germinate readily and young plants 

 can be- easily transplanted. In 1037 in addition to our regular 

 quota, sample lots of seed for nursery production were collected 

 from the mountains .above Miami, Arizona. The Baboquivari Moun- 

 tains offer another desirable form. The plants from the latter 

 piece grow to bo trees twenty feet high or more and as much as one 

 .foot in diameter at the butt, 



Cercocarpus le dif ol ius is another Mountain Mahogany, forming 

 a well shaped tree well worthy of trial as an ornamental. It is 

 not uncommon In the Grand Canyon and in mountain ranges of southern 

 Nevada and Utah. It is not comparable to C, mo nt anus for soil con- 

 servation or for forage. The wood of this and of C. montanus is 

 very hard and takes a beautiful shiny polish. It Ts well' suited 

 for use as bric-a-brac. 



