14 



YOLANDE HESLOP-HARRISON 



(e) (f) 



Fig. 6. Characteristic forms of stigmatic disc in British Nuphar taxa. (a)-(c) N. lutea; (d) N. intermedia; 

 (e) " introgressed " N. punii/ti; and (f ) N. pumi/a. N. /utea from Ellesmere and Tregaron, other sources 



of material as in Fig. 2. 



50i 



i 



30- 



20- 



10 



....^ Avinlocfian colony 



10 



I 

 I 



I 

 I 



•I 

 :i 

 il 

 :i 

 il 



!| 



jl 



N. intermedia 



J" 



:i 

 |i 



12 13 14 



Carpel number 



Fig. 7. Frequency histograms of " introgressed " N. pwuila, N. pumila and N- intermedia, 



