145 
NOTES ON POTAMOGETON. 
By Arruur Beyyert, F.L.S. 
(Continued from Journ. Bot. 1901, p. 201.) 
Potamogeton Morongii, nov. sp. Section (Natantes) Hetero- 
phyllit Koch. Lower part of stem striated, and spotted (much as 
in P. pulcher Tuckerm.); with numerous partitions which show 
notably when dry (much as in Juncus), but cease where the first 
g yllodia ( 
from bright green to blackish green). Upper leaves lanceolate to 
acute, strongly nerved, not winged ; peduncles slightly thickened 
in the middle ; spikes man -flowered; perianth segments reniform- 
t 
straight (the style forming a continuation of the face, not recurved), 
dorsal rounded, bluntly tricostate, with a projection towards the 
s 
and leaves resembling those of P. polygonifolius, and the fruit 
allied to P. americanus Cham. It also resembles, in the submerged 
A species with the habit of P. variifolius Thore,* the stipale 
- Oakestanus Robbins, but in that the structure of the leaves is 
similar to those of P. natans L., though much smaller; while in 
Morongii they have the structure of polygonifolius Pour. ; the 
Spikes also are longer, and the fruit different in the American 
species, 
This species is a good instance of the variability in shape of the 
fruit in maturing ; a series taken off one spike would almost cer- 
tainly pass for different species, if considered by themselves. Ripe 
fruit and that alone should be considered in this genus: and while 
such species as P, Javanicus Haskl., P. Miduhikimo Makino, and 
P. cristatus Regel & Maack are almost (quite ?) impossible to 
Separate if only in foliage ; with ripe fruit they can be separated by 
the touch alone, without using one’s eyes. 
name this species after my late friend Dr. Thomas Morong, 
of Columbia College, New York, in whom we have lost one of the 
most devoted students of the genus, and whose kindly help I shall 
never forget. 
* Is this plant known to produce fruit ? 
Journat or Botany. Vou. 40. [Apric, 1902.) M 
