232 ANNALS OF SCOTTISH NATURAL HISTORY 



this variety grows at upwards of 3000 feet, and far away from 

 the influence of C. approximata. We must seek for some 

 other explanation as to the cause of the variation than hybridity, 

 at any rate so far as C. approximata is concerned. On Ben 

 Lawers I gathered it away from C. helvola, in micaceous bogs, 

 with C. echinata. 



C. canescens, L., var. robustior (Blytt). At about 2300 feet on 

 Lochnagar and on the tableland above Glen Callater, South 

 Aberdeen ; and on Ben Lawers at 300 feet, and at lower 

 elevations. 



C. helvola, Blytt. Ben Lawers 1898, teste Pfarrer Kiikenthal. On 

 some specimens of this year's gathering he remarks : " Probably 

 C. canescens x echinata, but much nearer C. canescens than the 

 specimens sent last year. The spikelets are almost quite sterile. 

 The sacs are more elliptic than oval, and somewhat longer 

 beaked than in C. canescens, otherwise the difference from C. 

 canescens, var. dubia, is very slight." The synonyms of C. echinata 

 and C. canescens are C. tetrastachya, Traunst, C. Cafiischii, 

 Briigg., in " Jahrb. d. Nat. Ges. Graub.," p. 119, 1880, and C. 

 biharica, Simk., " Enum.," p. 546, 1886. I may add that 

 both the Rev. E. F. Linton and E. S. Marshall believe the 

 Lawers plant to have the suggested combination. It is con- 

 sidered by many botanists, e.g., Christ and the younger Blytt, 

 that C. helvola is a more or less stable hybrid of C. canescens with 

 C. approximata (lagopina) see my paper in " Journ. Linn. Soc.," 

 xxxiii. (1898), pp. 458-464, where these botanists agreed in 

 identifying the Lawers plant with C. helvola. I pointed out that 

 C. approximata in its nearest locality is some sixty or seventy 

 miles away from Ben Lawers, unless indeed it has escaped obser- 

 vation, or has died out, neither suggestion being very probable ; 

 whereas C. echinata is constantly associated with canescens in 

 these mountain bogs. I still am unable to see conclusive proof 

 of the presence of echinata in the Lawers helvola, although 

 Kiikenthal tells me he considers the longer beak of the 

 perigynium affords that evidence. I made a careful examination 

 of the forms of C. canescens and C. echinata as they grew 

 together ; but there was no difficulty in referring to one species 

 or the other the various forms ; and the foliage appeared to 

 afford a good character for this separation. In the young 

 stage the spikes of many sedges are very perplexing. All the 

 plants of helvola had the foliage of mountain canescens, while 

 the darker and more rigid foliage of etAinafa-fatms appeared 

 to be very constant. As Kiikenthal says, the differences 

 between C. canescens, var. dubia, and C. helvola are very slight, 

 and I see greater difference between C. Zahnii (an acknowledged 

 hybrid of C. canescens, in a mountain form, and C. approximata'] 



