GENERA OF GRASSES OF THE UNITED STATES. 127 



species possessing a palea. Prom this standpoint the type species would be 

 Agrostis spica-venti, which is referred by many botanists to Apera but 

 which is here included in Agrostis. However, the description of Agrostis in 

 the fifth edition was not written by Linnauis for that edition. It was copied 

 f:*om the first edition, published in 1737, at which time LinnaBUs's concept of 

 Agrostis was chiefly based on Stipa calamagrostis. By the time the Species 

 Plantarum was prepared his concept of the genus Agrostis had changed, but he 

 did not make the corresponding change in the description in the fifth edition 

 of the Genera Plantarum which he prepared at the same time. It seems best, 

 then, to ignore this description and select the type species from the economic 

 species. Therefore A. stolonifera * has been selected as the type species of 

 Agrostis. Several of the original species are now referred to other genera: 

 .1. miliacea and A. paradoxa to Oryzopsis; A. arundinacea to Oalamagrostis ; 

 A. minima to Mibora ; A. virginica and A. indica to Sporobolus. 



Vilfa Adans., Fam. PI. 2: 495. 1763. Adanson cites " Gramen canin. supin. 

 C. B. Theat. 12 " arid in the index, " Gramen canin. supin. minus C. B." Lin- 

 naeus 2 gives under Agrostis stolonifera the citation, " Gramen cariinum supinum 

 minus Scheuch. gram. 128." Scheuchzer 8 credits the citation to C. Bauhin. 

 Therefore Agrostis stolonifera L. is the type of Vilfa Adans. 



Apera Adans.. Fam. PI. 2: 495. 1763. Adanson refers directly to "Agrostis 1. 

 Lin. Sp. 61." The first species of Agrostis described by Linnaeus in his Species 

 Plantarum (p. 61) is A. spica-venti, which becomes the type of Apera. 



Trichodium Michx., Fl. Bor. Amer. 1: 41, pi. 8. 1803. Two species are de- 

 scribed, T. laxiflorum and T. decumbens. The first species, iliustiated in plate 

 8, is the type. This is the same as Afrostis hiemalis. Trichodium decumbens 

 is the same as A. perennans. Michaux distinguished the genus from Agrostis 

 by the absence of the palea. 



Agraulus Beauv., Ess. Agrost. 5, pi. 4, f. 7. 1812. Two species, based on 

 Afjrostis canina L. and A. alpina Willd., are included, the first being figured and 

 therefore the type. 



Anemagrostis Trin., Fund. Agrost. 128. 1820. Two species, based on Agrostis 

 spica-venti L. and A. interrupta L., are included, the first of which is taken as 

 the type. 



Notonema Raf., Neogenyt. 4. 1825. A single s-pecies is included, Agrostis 

 arachnoides Ell. (A. elliottiana Schult.) 



Podagrostis Scribn. and Merr., Contr. U. S. Nat. Herb. 13 : 58. 1910. Based 

 upon Agrostis, section Podagrostis Griseb. in Ledeb. Fl. Ross. 4: 436. 1853. 

 A single species, Agrostis aequivalvis Trin., referred here in each case. A. thur- 

 beriana Hitchc. also belongs to this group, which forms a section of Agrostis. 



In Agrostis spica-venti, A. aequivalvis,. and A. thurberlana the 

 rachilla is prolonged behind the palea as a minute bristle or stipe, 

 and the lemma and palea are nearly equal and about as long as the 

 glumes. The palea is obsolete in many species (which have been 

 separated by some authors under the generic name of Trichodium), 

 and is much shorter than the lemma in several other species. The 

 awn, when present, may arise from the back of the lemma just above 1 



1 See Hitchcock, Bot. Gaz. 38:141. 1904. On the basis of the specimen in the Lin- 

 naean Herbarium and of the synonymy, the name A. stolonifera was there applied to the 

 species called A. vertictllata Vill. But on reconsideration it seems best to accept the 

 name cis applied by Swedish botanists. Linnaeus was most familiar with the Swedish 

 grass, and cites as the first synonym under A. stolonifera the phrase name he had applied 

 to it in his Flora Suecica. He confused with this the South European species, A. ver- 

 ticillata, a specimen of which in his herbarium he marked " A. stolonifcra/' but we may 

 assume that he intended to apply the name A. stolonifera to the grass from Sweden. In 

 the latter work Linnaeus states that the plant is known popularly as Kryp-hwen. Dr. 

 Carl Lindman, who has kindly sent a series of specimens of the species in question, states 

 in a letter that the grass in Sweden called Krypven (the modern spelling) is the species 

 described by Swedish botanists as A. stolonifera. This has a long ligule, an open panicle, 

 and an erect culm decumbent at base or producing stolons. 



2 Sp. PI. 62. 1753. 3 Agrost. 128. 1719. 



