NOTES ON POTAMOGETON 161 
MIFRUCTUS nov. hyb. pe obtusifolin x Friesii ?) 
P. obtusifolius M. & K. Lake Glino,. near 
Niedesh, leg. R. Cas aspary.” 
Pr. Posen, Prussia 
g cimen, whic h I think may be named as above. It 
has the spikes, peduncles, and stipules of Friesiz, but the two 
heads of fruits are more like obtusifolius ; all the other spikes are 
interrupted (as in Friesii) and sterile; the flowers apparently 
never opened. On one spike only three fruits are perfect, all the 
rest. are abortive. The leaves are mostly 3- but occasionally 5- 
veined, though the two outer ones are less distinct. The leaves 
of obtusifolius often curl in drying, or are puckered at the margins, 
but there is none of this in the specimen under notice; the width 
and apex of the leaves are too variable to give definite ‘characters. 
Usually eas leaves of Friesii are more strict than obtusifolius. It 
is not always easy to arate some forms of these two plants ; 
separ. 
that | Fosasis occasionally simulates the latter closely is shown by 
specimens I possess named “P. mucronatus Schrad. Sweden, 
2, 8, 1882. C. O. Schlytar” from Dr. Tiselius; these are cer- 
tainly obtusifolius, yet the apices of the leaves are much more like 
Friesvi than obtusifolius. The specimen that most accords with 
this is a North American one, “ P. obtusifolius M. & K. cum spica 
interrupta Hastings Co. T. Morong.” This is undoubtedly 
Friesit. ish German and American botanists interested in the 
genus ts visit these ‘localities ‘nd publish the result. 
the grass-leaved species P. Friesit has page rong 
in various herbaria un nam - 
zosterflins, erron Berchtoldii, pustllus, hence. and 
pect 
., 26, 
ete named ees him amplifolius ; but in 1881 he sent other 
imens, arking: “Last year I sent 
Apponan ng Pond, which were marked, ‘form of amplifolius, with 
coriaceous lower leaves.’ I now send others collec ) same 
spot this year, wad undoubtedly the same species. I have satisfied 
Ma that it is not amplifolius, but only a pec 
P. pulcher, produced perhaps by the sonition of the water. 
None produced flower or fruit.” So far as eye-judgment goes, I 
li rong’ or in 
umerous 
leaves. Tin tokh, epecien: Bray 3 Sie Rene ? and, if so, is it a 
hybrid between two? 
I am aware I am treading on Saige — when I 
