THE CYTOGENETICS OF CAREX FLAVA AND ITS ALLIES 131 



Table 1 



Chromosome numbers of the C. flava aggregate 





Haploid 



Number of 





Species 



number 



plants sampled 





C. extensa Good. 



30 



4 



Rhos Neigr, Anglesey. 



C. flava L. 



30 



4 



Roudsea Wood, Haverthwaite, Lanes. 





30 



1 



Malham Bog, Yorks. 





30 



2 



Preda, Graubiinden, Switzerland. 





30 



1 



Lake Carezza, W. Dolomites, N. Italy. 



(a) C. lepidocarpa Tausch 



34 



1 



Wicken Fen, Cambs. 



subsp. lepidocarpa 



34 



1 



Fulbourn Pond, Cambs. 





34 



3 



Wittering Marsh, Northants. 





34 



1 



Gordale Scar, Malham, Yorks. 





34 



1 



Malham Tarn, Yorks. 





34 



1 



Moughton Scar, Yorks. 





34 



3 



Widdybank Fell, Teesdale, Durham. 





34 



1 



Gotland, Sweden. 





34 



1 



Tiefencastel, Switzerland. 



(b) C. lepidocarpa subsp. scotica 



34 



1 



Cwm Glas, Snowdon, Caernarvon. 



E. W. Davies 



34 



1 



Carn Eige, Cannich, Inverness. 





34 



I 



Inchnadam^ph, W. Sutherland. 





34 



1 



Preda, Graubiinden, Switzerland. 





34 



1 



Albula, Graubiinden, Switzerland. 



C. mairii Coss. & Germ. 



34 



4 . 



Lumbreras, Spain. 



C. demissa Hornem. 



35 



2 



Shapwick peat moor, Somerset. 





35 



1 



Bredon Cloud Wood, Leics. 





35 



3 



Strines Moor, Derbyshire. 





35 



1 



Little Dun Fen, Westmorland. 





35 



3 



Loch Tummel, Perth. 





35 



2 



Cannich, Inverness. 





35 



1 



Cwm Glas, Snowdon, Caern. 





35 



1 



Furnols, Echandelyse, Auvergne, France. 





35 



1 



Lac de la Faye, Auvergne, France. 





35 



1 



Issoire, Central France. 





35 



1 



Font Romeu, E. Pyrenees, France. 



C. serotina Merat 



35 



1 



L'Ancresse, Guernsey. 





35 



1 



Frensham Pond, Surrey. 





35 



2 



Fulbourn Pond, Cambs. 





35 



2 



Rhos Neigr, Anglesey. 





35 



2 



Hale Moss, Bentham, Lanes. 





35 



1 



Monea, Ireland. 





35 



2 



Hokatorp, Skane, Sweden. 





35 



2 



Alvar, Oland, Sweden. 





35 



2 



Gotland, Sweden. 



C. serotina var. cyperoides 



35 



1 



Shapwick peat moor, Somerset. 



C. scandinavica E. W. Davies 



35 



1 



Sweden. 





35 



1 



Loch Torridon, W. Ross. 



The meiosis appears to be more abnormal and irregular when the parents of the 

 hybrid are very dissimilar, and have widely different chromosome numbers. The 

 metaphase I, described above, represents a hybrid between C. demissa (n = 35) and 

 C. hostiana (n = 28). In an interspecific hybrid between two more closely related species 

 such as C. demissa (n = 35) and C. lepidocarpa (n = 34), or C. demissa (n = 35) and 

 C. serotina (n == 35), meiosis is more normal, and apart from a few univalents and perhaps 

 one conglomerate group of chromosomes forming a chain, the rest are arranged on the 

 metaphase plate as bivalents (Plate 13, figs. 17-20). Thus a fairly high degree of homology 



