DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 347 



Glyceria arctica, Hk,, is certainly only a starved state of Jluituns. Durand. gives 

 this as a native of Greenland, lat. 68° N, 



PoA airoides, Nutt., is identical with Atrojns cUstans, Griseb. 



P. angtistata, Br. (Atrojns, Griseb.), is kept distinct by Grisebach with P. Nutkaensis 

 as a synonym ; it is a very arctic form. 



P. angustifolia, L., is pratensis y of Grisebach ; it is rare in the arctic regions. Anders- 

 son refers it, with a query, to serot'ma. 



P. trivialis, L., is kept distinct by Grisebach, Pries, Andersson, and almost all authors ; 

 it is also arctic. Pries doubts the identity of the Linnsean plant. 



P. nemorcdis, L. I have followed Mum-o in bringing together the following names, 

 which, whether species or no, are not to be discriminated by arctic stunted specimens ; 

 he considers them all forms of one : — 



P. ccesia. Smith, is kept up by Grisebach and Andersson, with aspera, Gaud., as a 

 synonym; Pries also keeps it distinct; Andersson indicates its extremely close affinity 

 with nenioralis. 



P. Grcenlandica, Steud., is nothing but serotina, Ehr., which is kept up by Grisebach, 

 Pries, Asa Gray, and Andersson. 



P. bryopJiila, Tr. Called arctic by Grisebach, who has never seen the plant ; but I do 

 not find the locality (Pret. Senjawin) in any map. Munro reduces it to nemoralis. 

 P. Vahliana, Liebm., Plor. Dan. 2401, is but a slight variety of nemoralis. 

 P. laxa, H^nke. Grisebach, Andersson, and Pries all keep this distinct ivom flexuosa. 

 In ' Plor. Bor.-Am.' they are treated as synonyms. Por remarks on its affinities, see 

 Andersson (Gram. Scand.). 



P. Cenisia, AIL Grisebach keeps this distinct, but refers Ceuisia of Pries's Ilerb. 

 Norm, to arctica, Br. {Jlexuosa, Wahl.). Pries vefevs flexuosa, "VYalil., to Cenisia. Anders- 

 son considers Cenisia hardly distinct from arctica, Br. 



P. arctica, Br. Kept distinct by Grisebach, who Tas>k&'& jlexuosa, Wahl., a synonym of 

 it. It b,Jlexuosa /3 of Trinius, and laxa, Br. in Ross's Voyage. 



P. abbreviata, Br. Unknown to Grisebach, and reduced by Munro. Pries and Anders- 

 son reduce abbreviata, Blytt, to Cenisia, var. depavperata. 



Pestuca Bicliardsoni, Hook. Durand, on Torrey's authority, gives what Torrey 

 doubtfully considers a variety of this plant as a native of Greenland. I know of no species 

 to which Bicliardsoni is closely allied, except the Bocky Mountain var. F. scabrella, of 

 which it may be a hirsute form. 



P. ovina, L. I follow Munro and Bentham in reducing r^ibra and duritiscula, and the 

 former authority in bringing Kceleria hirsuta and F. brevifoUa here. The latter is a 

 marked smaU form, but passes gradually into rubra. Andersson keeps up ovina, duritis- 

 cula, and rubra, bringing arenaria under the last, and sabtilosa under the first. Grise- 

 bach keeps up ovina, L., with duriuscula as var. S ; also rubra, L., with arenaria as var. 

 |3, and Kceleria hirsuta (of which I know nothing) as distinct from both ; but Munro 

 reduces all to ovina, L, Pries unites arenaria and rttbra, keeping durmscida and ovina 

 distinct. 



VOL. XXTII. 3 A 



