1921] Wiegand, — Echinochloa in North America 61 



Jalisco, 1903, E. W. D. Hoi way, no. 5,096; Zamora, Michoacan, 

 1901, C. G. Pringle, no. 8,480 (type in Gray Herb.). 



This plant is provisionally appended to E. echinata as a variety, 

 with which species it is most closely related, and from which it differs 

 in characters of degree only. A wider range of specimens may show 

 it to be a distinct species. Pringle's no. 8,480 was listed by Hitch- 

 cock under E. oplismenoides. 



In 1809 Willdenow (Enum. PI. Berol. 1032) published Panicum 

 echinatum, the description containing the statement: " . . . 

 glumis aristatis muricato cchinatis. . . . Habitat in America 

 meridionale." It was similar to P. crusgalli, he says, but "minus 

 et valvulis muricato-echinatis." He gave as a synonym P. muri- 

 catum Hornem., Cat. Hort. Haf., p. 28, but the writer has not had 

 access to the Horneman reference. There are very few species of 

 Echinochloa in Central America, and only the present species agrees 

 at all closely with AVilldenow's description. Although several authors 

 have refused to take up the name echinatum and others have treated 

 it in widely different ways, its application to this species seems suf- 

 ficiently clear to warrant its acceptance. Judging from the descrip- 

 tion, the Oplismcnus crus-pavonis HBK. can be no other than the 

 present species. The Panicum sabulicolum Nees. is more question- 

 able. It was described from sandy ground in Para, and from Monte- 

 video and Paraguay. The last two regions and possibly the first 

 are outside the range of E. echinata as known to the writer. The 

 author recognized it in addition to P. crus-pavonis which he made a 

 synonym of P. echinatum Willd., moreover his description does not 

 fit our species very well. Trinius seems to have figured as Panicum 

 sabulicolum (Gram. ii. no. 163, 1829) a specimen of E. echinata, and 

 a somewhat similar confusion seems to exist in Doll's treatment 

 (in Mart. Fl. Brasil. ii. pt. 2, 142, 1842). Kunth (Enum. Plant, i. 

 145, 1833) made P. sabulicolum a synonym of P. echinatum, but 

 separated it from P. crus-pavonis. It is possible that Nees had in 

 hand some member of this genus not included in the present study, 

 material of which is not available. 



7. E. Walteri (Pursh) Nash' in Britton's Manual 78 (1901). 

 Panicum Walteri Pursh, Fl. Amer. Sept. i. 66 (1814), not Muhl. 



i Heller in bis Cat. N. A. Plants, ed. 2, 21 (1900) listed E. Walteri (Pursh) but 

 with no description or synonymy. Notwithstanding that Pursh's name is in paren- 

 thesis, the reference is too vague to warrant the acceptance of this as a valid pub- 

 lication of the combination. 



