78 



ELIZABETH W. DAVIES 



The data used in drawing the histograms were obtained from collections made 

 during the past two years in this country, and augmented by European herbarium 

 material. 



The shape of the perigynia is another good character, for C. flava and C. lepidocarpa 

 have arcuate-deflexed perigynia, which are gradually attenuate into a beak, while those 

 of C. demissa are only slightly curved, and the remaining two species have straight 

 perigynia. In contrast to the other species the perigynia of C. scandinavica are not 

 inflated, but tightly enclose the nut. 



Finally the beak length is a useful character, and, as might be expected, decreases 

 proportionately with the decrease in perigynia length. Thus the beak lengths of the 

 five species are as follows :- 



C. flava 2-0 -2'5 mm. 



C. lepidocarpa ssp. lepidocarpa 15 mm. 



C. lepidocarpa ssp. scotica 1-5 mm. 



C. demissa 1-0 mm. 



C. serotina 0-25-0-5 mm. 



C. scandinavica 0-25 mm. 



5. Female glumes 



Finally the colour of the female glumes, normally a rather unreliable and variable 

 character, has been found useful in distinguishing certain members of the complex. Thus 

 the female glumes of C. lepidocarpa ssp. lepidocarpa are pale brown, hyaline and caducous, 

 while those of the ssp. scotica are dark chestnut-brown and usually persistent, so giving 

 the female spikes a characteristic dark appearance, 



