238 STAND LEY - . FLORAS OF NEW MEXICO AND ARGENTINA 



Most of these are species of wide distribution, some of them, 

 like Phragmites phragmites, Polypogon monspeliensis, and Eleo- 

 charis palustris, extending to the Old World. Polypogon mon- 

 speliensis may even be adventive in the Western Hemisphere. 

 Others of the list, like Paspalum distichum, Juncus mexicanus, 

 Heliotropium curassavicum, and Petunia parviflora, have an ex- 

 tended range in the warmer parts of North and South America. 

 Several of the other species, however, are not continuous in 

 their ranges, being restricted to the temperate parts of the two 

 American continents. Among them are Festuca octoflora, Mono- 

 lepis nuttalliana, Silene antirrhina, Halerpestes cymbalaria, 

 Daucus pusillus, Solanum elaeagnifolium, and Linaria canadensis. 

 Some of these are plants which range widely in the United States, 

 but the Monolepis, Halerpestes, Daucus, and Solanum are typi- 

 cally southwestern plants. Solanum elaeagnifolium is a charac- 

 teristic plant of southern New Mexico and Arizona and of western 

 Texas. 



In addition to the species listed which are common to the two 

 regions, certain others occurring in the Argentine area appear 

 elsewhere in the southwestern United States. Veronica anagallis- 

 aquatica L. occurs in New Mexico and Arizona, and Lythrum 

 hyssopifolium L. and Scirpus riparius Presl in California. Pani- 

 cum urvilleanum Kunth is known only from Arizona, California, 

 Chile, and Argentina. Malacothrix coulteri Gray is common to 

 southern California and Argentina. Chenopodium ambrosioides 

 L., Potamogeton filiformis Pers., and Hordeum pusillum Nutt. are 

 widely diffused in North America. 



More interesting and suggestive is the following list of paired 

 species. The species listed in the lefthand column are Argentine, 

 while those in the righthand column are certain New Mexican 

 ones which bear a close resemblance to them. A few of those cited 

 from New Mexico do not actually occur in the Mesilla Valley out 

 they are found at New Mexican points not far distant. 



Argentine Species New Mexican Analogues 



Azolla filiculoides Lam. Azolla caroliniana Willd. 



Ephedra ochreata Miers Ephedra trifurca Torr. 



