CiKCULAR No. 34— (Agros. 85.) Issued May 24, 1901. 



United States Department of Agriculture, 



DIVISION OF AGROSTOLOGY. 



[GRASS AND FORAGE PLANT INVESTIGATIONS.] 



F. LAMSON-SCRIBNER, Agrostologist. 



ARISTIDA PURPUREA NUTT., AND ITS ALLIES. 



The species of Aristida belonging to the section with very une- 

 qual empty glumes, occurring in the United States, never have been 

 clearly understood, and an attempt is here made to show the rela- 

 tionships of the many species, or supposed species, which have been 

 described by various authors. While in some instances the conclu- 

 sions are not wholly satisfactory, and some species are interpreted to 

 include many different forms, it has been thought that the only 

 proper way to treat this group is on broad lines. Under the present 

 tendency to multiply species, some authors would doubtless add 

 many new species in this group ; but we are of the opinion that such 

 a multiplication of species would add to rather than lessen the diffi- 

 culty in determining the limits of the several species. There appears 

 to have been a tendenc}^ to overlook old published species which, by 

 reason of their very short or imperfect descriptions, are doubtfully 

 known, and in the present paper an attempt is made to correlate 

 the old species and varieties, with the belief that, even if these are 

 wrongly interpreted, such work is often of more value than promis- 

 cuous publications of many new species with no attempt to determine 

 the limitations of those already published. Among the old species 

 and varieties in this group are Aristida americana L,., A. fascicu- 

 lata Torr., A. purpurea Nutt., A. dispersa T. & R., A. purpurea 

 berlayidieri T. & R., A. purpurea hookeri T. & R., A. fendle- 

 riana Steud., A. longiseta Steud., A. roiiieriana Scheele, A. cequi- 

 ratnea Scheele, A. filipendula Buckle}', and A. curtiseta Buckley. 

 — F. Lamson-Scribner. 



There are in the U. S. National Herbarium the types of the several 

 species and varieties described by Dr. Vasey, and also cotypes of the 

 following species: Aristida longiseta Steud. (978 Fendler), A. 

 fendleriana Steud. (1)73 Fendler), A. purpurea berlandieri T. &R. 

 (1777 Berlandier), A. purpurea hookeri T. & R. (293 Drummpnd), 

 and, apparently, A. cequiramea Scheele (562 Lindheimer). Through 

 the courtesy of Mr. Stewardson Brown, curator of the botanical sec- 

 tion of the Philadelphia Academy of Natural Sciences, we were able 

 to examine the types of A. purpurea Nutt., A. jiJipendida Buckley, 

 and A. curtiseta Buckley. Mr. George V. Nash kindly matched 

 specimens with the type of Aristida fasciculata Torr., in the 

 herbarium of Columbia University. 



Of the above-mentioned species, Aristida americana L., was first 



