GENTIANACEAE 



rosettes of grayish green leaves, tall leafy stems and spikes of 

 greenish flowers. It is listed among the poisonous plants. 



Frasera pan iou lat a is a curious plant, related to P. speciosa , 

 and found only in desert sands of New Mexico and Arizona. It has o 

 large, fleshy root that grows deep into the sand. The stems are 

 slender, the leaves rather narrow and white margined. As far as is 

 known it is valueless. 



APOCYEA.CEAE 



Ilapl ophyton cimicidum is a very rare plant in our region, 

 being confined to extreme southwestern ranges' in Arizona. It, 

 however, is more abundant southward, becoming a plant of some im- 

 portance in portions of the Tropics. It is an herbaceous perennial 

 with very slender steirja and leaves, bright yellow flowers and long, 

 narrow fruits which arc always 121 pairs. This plant scorns to be 

 quite heavily browsed whore it occurs in stock ranges and is a good 

 erosion control plant. its use as d soil binder or for forage, how- 

 ever, should be questioned until further investigations of it have 

 been made. The Mexicans apply the term" dcor-ki 1 ler " to the plant, 

 indicating that it is poisonous and it has been used for many decades 

 in Mexico to prepare a solution for killing insects. Our chief 

 interest in the plant is its possible use for the manufacture of a 

 commercial insecticide. A beautiful bed of it is growing on the 

 nursery at Tucson and seed lias been sent to !*r. Russell at Texas 

 A. c. ?.!• , and to Dr. Sievcrs at Washington, D. C, for experimental 

 work. 



♦Mac r o s iphon ia brachy siphon is a low shrub confined in our 

 region to southern Arizona but common in northern I.exico. It has 

 a wide-spreading root system in which the roots sprout freely and 

 as it occupies the heads of small draws it constitutes a good, in 

 fact one of bhe best, erosion control plants in regions where it 

 grows. Funnel-shaped flowers and opposite leaves suggest the 

 Periwinkle, which is common in many flower gardens. T 'acres iohonia 

 is related to the Periwinkle and lias a similar habit. The flowers, 

 however, are white or occasionally hove a pinkish tinge and are 

 very fragrant. The shrub is quite heavily browsed but withstands 

 grasing well. Up to the present it has not been used in revegeta- 

 tion work but its qualities recommend it for this and for use as 

 an ornamental . 



AS CLEP IADACEAE 



Asclopias albicans. Several of the Hilkwcods have been 

 tested for choir rubber content. This and the following two species 

 appear to be our best rubber producers. A. albicans is confined 



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