DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 317 
Glyceria arctic*, Hk., is certainly only a starved state of Jluilans. Durand givi 
this as a native of Greenland, lat. 68° N. 
Poa airoides, Nutt., is identical with Atropk distans, Griseb. 
P. angustata, Br. (Atropis, Griseb.), is kept distinct by Grisebach with P. Xufhaensis 
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 serotina. 
P. trivialis, L., is kept distinct by Grisebach, Fries, Andersson, and almost all authors ; 
it is also arctic. Pries doubts the identity of the Linnaean plant. 
P. nemoralis, L. I have followed Munro in bringing together the following names, 
which, whether species or no, are not to be discriminated by arct ic stunted specimens ; 
he considers them all forms of one : 
P. ccesia, Smith, is kept up by Grisebach and Andersson, with asj>era, Gaud., as a 
synonym; Pries also keeps it distinct; Andersson indicates its extremely close affinity 
with nemoralis. 
P. Grcenlandica, Steud., is nothing but serotina, Ehr., which is kepi up by Grisebach, 
Pries, Asa Gray, and Andersson. 
P. bryophila, 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, Haenke. Grisebach, Andersson, and Fries all keep this distinct ivom Jlcxuosa . 
In ' Plor. Bor.-Am.' they are treated as synonyms. For remarks on its affinities, se< 
Andersson (Gram. Scand.). 
P. Cenisia, All. Grisebach keeps this distinct, but refers Cenisia of Frics's Herb. 
Norm, to arctica, Br. (flexuosa, Wahl.). Fries refers Jlexuosa, TVahL, to Cenisia. Anders- 
son considers Cenisia hardly distinct from arctica, Br. 
P. aretica, Br. Kept distinct by Grisebach, who makes Jlexuosa, Wahl., a synonym of 
it. It is Jlexuosa /3 of Trinius, and laxa, Br. in E-oss's Voy 
P. abbreviata, Br. Unknown to Grisebach, and reduced by Munro. Fries and Anders- 
son reduce abbreviata, Blytt, to Cenisia, var. depanperata. 
Pestuca JRichardsoni, 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 Bichardsoni is closely allied, except the Rocky Mountain var. F. scahrella, of 
^hich it may be a hirsute form. 
P. ovina, L. I follow Munro and Bentham in reducing rubra and duriuscula, and the 
former authority in bringing Kceleria Mrsuta and F. brevifolia here. The latter is a 
marked small form, but passes gradually into rubra. Andersson keeps up ovina, dunus- 
cula, and mbra, brineinff arenaria under the last, and sabulosa under the first. Grise- 
o*"o 
bach keeps up ovina, L., with duriuscula as var. l\ also rvbra, L., with arenaria as var 
ft and Kceleria Mrsuta (of which I know nothing) as distinct from both ; but Munr< 
reduces all to ovina, L. Fries unites arenaria and rubra, keeping duriuscula and ovim 
distinct. 
VOL. XXIII. 
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