296 NOTES ON POTAMOGETONS. 
covsidered among European botanists as Roth’s, and gives excellent 
reasons for his hesitation. 
ave been for some time trying to unravel the difficulties that 
surround the question, and offer these remarks as a contribution to 
of the results given. We have no certain knowle of any 
specimen of Roth’s species being preserved in any herbarium; but 
there are at Mu ecimens in Schreber’s herbarium, named ag 
such, and gathered “In Seebach, 1775,” and others, ‘‘In Seebach, 
82.” It seems to me a reasonable inference that these specimens 
are from (or seen by) Roth; the more so because there are other 
8 @ same collection actually received from Roth, and 
Si are the plant we call fluitans in England 
r. Morong’s remarks that specimens sent to hi 
France under Roth’s name have fruit “ otally dissimilar’ from the 
Necker plant sent him by Dr. Tiselius. i 
Loire (Lloyd) are precisely our plant. A specimen from “ Varde, 
leg. Hempel,” which (except that it has no fruit) might well have 
, * 
After comparing the whole of the specimens I possess in fruit 
named P. fluitans Roth, I cannot discover any real difference, 
except such as proceeds from degrees of ripeness. Not having seen 
Dr. Morong’s lrench specimens, I can offer no explanation; these 
Raids is-ec-cacur a +t . © variation in the leaves in this 
titidie in 8 '. at no value can be laid upon Specimens named, 
From Australia I haye seen nothing th 
‘ae . at could be referred to 
luitans. In Polynesia, of the two species named by Chamisso 
aack “Ad ostium fl. Lena, Siberia,” I find to belong to my 
curs ure,’’ in her i 
ris. 
oO 
& 
t name, there being some difference in the fruits; but 
— alteration takes place in the fruits from half to full maturity, so that 
caution is needed not to describe merely conditions of growth. 
