_ NOTES ON POTAMOGETON 247 
sent season. I should be greatly obliged to readers of the Journal 
4 sigs Bs for fresh material of any species except the common 
pinym 
With rega: ard to see ar Engelmann’s conception was a very 
broad one. Under C. obtusiflora H. B. K., includ ding C. Tinei, he 
defines seven va arieties, respectively from South Am merica, West 
Indies and Southern United States, ad Australia and China, 
£ C. racemosa Mart. he has five varieties, including C. suaveo- 
lens ; all aula American. 
ee of unequal length, are not const achhy so is any species 
that I have examined. Further, I am not sure that the lobes of 
the corolla are permanently inflexed in 5 say species 
DESCRIPTION or Prate 493. 
A. Cuscuta suaveolens Seringe—1. A half-expanded flower attached to 
axis, x 6. 2. A fully- expanded flower, x 6. 3. Coedits laid open, igor a 
attached stamens and sigh i Ser 4 A de tached scale, x 10. 5. Pistil, x 
Vinet Insenga ise i Flower-buds attached, showing the relatively 
long pedicels, x 6. 7. rs out 
oir ig 8. 8. ” Corelle of the ean laid open, showing the stamens neve scales, 
A scale from the sa x 20. 10. Pistil, x 10. 11. A fully- 
nae ed oe. Os = Coral, stamens, and scales of the same, the 
corolla-lobes straightened ou 
. Gronovii sae sony A tally. ro flower, x 6. 14. Calyx and 
vind ripe fruit, x 6. 15. Corolla laid open, showing stamens and scales, 
16. Ascale, x 10. 17. A 
NOTES ON POTAMOGETON. 
By Arruur Bennett, F.L.S. 
(Continued from p. 163.) 
Ons of the results of the recent monograph of Potamogeton by 
Dr. Graebner (Das Pflanzenreich, Heft. 31 (1907)) is to show ee 
necessary it is that correlation oe arieties over wide areas should 
e ma 
individuals. 
Out of the — hundred and sixty varieties, subvarieties, and 
forms that have bee: 
ates are taken ah in this latest work on the genus, leaving about 
two hundred unnoticed, while fifty-six new ones are given. This 
ae adds to the synonymy, and leaves future workers to dispose 
