Arctic Plants: Morphology and Synonymy 9 b 



Only one species, D. Fischeri, was known to Robert Brown, but since then 

 Ruprecht (I.e.) has described a second one, D. psilosantha, from Kolgujew island, 

 and a third one, D. micrantha nob., has been found in Labrador: Halton, and at 

 cape Henrietta Maria, Hudson bay. 



Of these D. psilosantha differs from D. Fischeri by the empty glumes being 

 "acutissimae, caudatae," and by the flowering glume being "(flosculi) glaberrimi, 

 acuminati," while in D. Fischeri the empty glumes are more or less obtuse and 

 the flowering glume obtuse and pilose at the base; the third species, D. micrantha, 

 differs from both by the small size of the mostly one-flowered spikelets, etc. 

 according to the diagnosis:' 



"Stoloniferous: culm slender, glabrous, about twenty-five cm. in height: 

 leaves very narrow, glabrous with prominent ligule : inflorescence a contracted 

 panicle with capillary branches: spikelets one or two on each branch, mostly 

 one-flowered: empty glumes unequal, very narrow and sharply pointed, mem- 

 branaceous: flowering glume acute, slightly hairy at the base, not exceeding the 

 superior empty glume: palet bidentate, a little shorter than the flowering 

 glume." 



Glyceria R. Br. 



The segregation of Atropis originated with Ruprecht'' and was accepted by 

 Grisebach in Flora Rossica: "genus a Glyceria imprimis stylo ad basin usque 

 simpliciter plumosa distinctum est." Meanwhile Parlatore ^ established the 

 genus Puccinellia containing the same species as Atropis and formerly by Elias 

 Fries ^ referred to his section Heleochloa of Glyceria. According to Fries (I.e. 

 1846) Glyceria consists of two sections: " Hydrochloa Hartm.," with the flowering 

 glume 7-nerved, and "Heleochloa Ft." with the flowering glume 5-nerved. 



As a section Atropis has been recognized by various writers, and much more 

 so than Puccinellia. Buchenau °, however, treats Glyceria and Atropis as distinct 

 genera, and this author is one of the very few who furnishes a sufficiently com- 

 plete diagnosis. In Gray's Manual (1908), Puccinellia is accepted as a genus, 

 though poorly defined as distinct from Glyceria; more recently we find the same 

 disposition by Fernald and Weatherby (Rhodora 1916), enumerating eleven 

 species as indigenous to eastern North America south of Hudson straits. 



However, in giving Puccinellia preference to Atropis Fernald and Weatherby 

 have certainly misunderstood Ruprecht, because this author has clearly demon- 

 strated that he considered Atropis and some other genera as being distinct from 

 Poa. And when Ruprecht states that: "E conditione glumarum generum 

 series fortasse sequens: Dupontia, Arctophila, Poa, Atropis cet," this author did 

 not mean that these: "from the condition of the glumes perhaps represent a 

 series of genera as follows: Dupontia cet.," but that the genera mentioned might 

 be arranged according to the structure of the glumes, as enumerated above; 

 series means in this connection sequence referring to the arrangement. More- 

 over, it seems unjust to ignore Atropis because the diagnosis of Puccinellia 

 by Parlatore is more complete; if such procedure be considered "the best for 

 serving the cause of sound nomenclature," as claimed by these authors, very 

 many genera of Linnaeus would suffer the same fate. 



By comparing the species of Glyceria, the classification proposed by Fries 

 (I.e.) appears the most natural, retaining the genus intact, as has been proposed 

 also by Duval- Jouve in his classic treatise: Doutes et priSres au sujet de quelques 

 espSces de Glyceria du groupe des Halophiles.' 



• Fedde's Repert, I.e. 



' Florae Samojed. Cisural. 1846. 

 » Fl. Ital. I. 1848. 



• Summa veget. 1846. 



' Flora d. nordwestdeutsch. Tiefebene, 189 ! . 



• Bull. Soc. Bot. France; Paris, 1863. 



