8 



Type locality: " Pensylvania. " General distribution: in wet meadows, Penn- 

 sylvania and Virginia, June-Jiily. 



The original description of this species and also Muhlenbnrg's description are 



given below. 



"Aira pallens aristata, panicula contracta, valvulis calycinis insequalibus, 

 flosculo altero aristato, altero mutico. Folia linearia, glabra, rigida, 

 subinvoluta, vaginis pubescentibus. 



E. Pensylvania 3Iiihlcvb." Sprengel, Mantissa Flora Halensis 33. 1807. 



"Aira pallens. Culmo tripedali erecto nodoso. Foliis lineari-lanceolatis 

 glabris, nodis glabris. Ligula retnsa ciliata. Vagina substriata. Pan- 

 icula contracta nutante. Ramis paniculse 5, ternis geminisque scabris, 

 ramulis alternis. Cal. gluma 2-valvis corolla minor, nervosa, scabra, 

 valvula una latiori ; altera lineari utraque acuminata niutica, bi- et tri- 

 flora, flosculo nno pedicellato, omnibus hermaphroditis. Cor. gluma 

 3-valvis puncticulata, flosculi sessilis mutica, pedicellati aristata, arista 

 paulo infra apicem sive dorsali contorta, pedicello flosculi Isevinec pubes- 

 cente. Stam. 3. Pist. 2. Semen glabrum. Radix perennis. Habitat in 

 pratis humidis et varietas omnino mutica in sylvis, floret Jtinio et iterum 

 Sept. Aira Pennsylvanica, Sprengel. Habitus Avence sesquitertioi, cf . 

 Athena j)alustris, Michanx." Muhlenberg Descriptio 84. 1817. 



In Muhlenberg's herbarium there are two sheets, one labeled ' ' 128 Aira pallens " 

 and the other " 129 Aira pallens var. aristata." In the first sheet are sev- 

 eral fragments of Deschampsia flexuosa Trin., Poa debilis, Torr. and an 

 Eatonia, probably Eatonia yiitida (Spreng.) Nash., while in the second sheet 

 there are specimens of Trisetum palustre Torr., and the grass described by 

 Vasey as a hybrid between Eatonia pennsylvanica and Trisetum, palustre, 

 the form here taken up as Eatonia pallens. It is at once evident from an 

 examination of Muhlenberg's description above, that this last form is the 

 plant described by Muhlenberg as Aira pallens. Muhlenberg erred in citing 

 Aira pennsylvanica Spreng., as a synonym, as this species is awnless and is 

 Eatonia nitida (Spreng.) Nash. 



Sprengel's description of Aira pallens does not exactly apply to our plant, as he 

 speaks of its subinvolute leaves and i^ubescent sheaths. It is very probable 

 that he had other species under the same name, possibly Eatonia nitida or 

 some species of Trisetum, as is the case in Muhlenberg's Herbarium. This 

 is more probable, because Sprengel received the material on which the spe- 

 cies was based, from Muhlenberg. 



This form was discussed by Vasey and also by Scribner ^ as a hybrid between 

 Trisetum palustre and Eatonia pennsylvanica, and in this discussion the close 

 relationships of Eatonia and Trisetum are pointed out with the conclusion 

 that the genus Eatonia should properly be placed in the Avenea' next to Tri- 

 setum and not in the Festucea', where it now is. In considering this form as 

 a species in the genus Eatonia, it is necessary to modify the character of the 

 genus so as to include this awned form. See Scribner, U. S. Dept. Agr., 

 Div. Agros. , Bui. 20 : 135, fig. I04, 1900. This species is at once distinguished 

 from Eatonia peymsylvanica (DC.) A. Gray, to which it is most closely 

 allied, by its awned second -flowering glume. 



The only specimens we have seen referable to this species is the one in Muhlen- 

 berg's Herbarium and a specimen collected at Hunting Creek, Alexandria, 

 Va., by Dr. Vasey, June 6, 1884. 



J 



1 Bot. Gaz. 9. 165-169. 1894. 



