8 MR. J. BALL OlS" THE FLORA 



of south latitude, only a few points at wide distances asunder 

 have been visited by botanists, and each of these has supplied 

 numerous species not yet known to grow elsewhere. Strong 

 confirmation of this opinion may, I think, be found in the fact 

 that a hurried visit to a valley situated in the most sterile portion 

 of the great range should have produced out of a total number 

 of about 210 indigenous species, 17 undescribed, to which I have 

 felt it necessary to assign names, besides five or six more, almost 

 certainly new, which I have preferred to leave unnamed. Of the 

 17 species, three are identical with plants, hitherto unnamed, ex- 

 isting iu European herbaria, and I feel sure that many more 

 Andean species remain to be added from this source. A slight 

 visit to the herbarium of M. Lombardi at Lima satisfied me that 

 a further considerable amount of undescribed materials must 

 exist among the collections of that gentleman and of other South 

 American botanists. 



The accompanying list of plants collected in the upper Eimac 

 valley, between the limits of 7,800 feet and 14,300 feet above the 

 sea, includes 224 species and six marked varieties, of which two 

 or three may hereafter be ranked as distinct species. Of the 

 plants enumerated nine appear to have been certainly introduced 

 by the agency of man, viz. : — Capsella Bursa-pastoris^ Lepidium 

 virginianuniy Erodium cicutarium, JErodium malacoides, Medicago 

 denticulata^ Melilotus indica^ Centaurea melitensis^ Solatium tube- 



rosuniy and Paspalum stoloniferuniy and I have thought it best to 

 omit these from the tables given below. To the list of intro- 

 duced species many botanists would add the following five : 

 Cerastium gJomeratum^ Stellaria media, Galium Aparine, GnapJia- 

 Hum luteo-album, and Poa annua. As regards each of these, 

 however, I think that the weight of evidence goes to prove that 

 their wide diffusion throughout the world, and specifically in South 

 America, is mainly due to agencies other than the interference of 

 man, and especially to transport by birds. 



Jn the subjoined table I have sought to exhibit the distribution 

 of the species collected in the upper Rimac valley, distinguishing 

 those found only in what I may call the lower temperate zone, 

 between 7,800 and 11,000 feet above the sea, from those found 

 only about Chicla, between 12,000 and 12,G00. The number in 

 the former category has been increased by 13 species, collected 

 by Mr. Ward above Matucana in the month of May, and not 

 tteen by me. 



