E. Tuckerman on New England Plants. 225 
cles ovatis, supremis plus minus rotundatis profunde cordatis 
tiolis subcanaliculatis seepius longioribus ; stipulis elongatis lineari- 
linguiformibus acutis; pedunceulis: longiusculis ; fructibus recenti- 
bus late oblique obovatis lunatis, stylo subapicali mucronatis, 
dorso tricarinatis, lateribus convexis in faciem acutam declivibus. 
P. pulcher, Tuckerm. Obs. in Sill. Journ., xlvi, p. 
Has. Ponds; Stoneham, Tewksbury, " apparently not very 
— but abundant where it occurs. F#. May, Jtine. — Fr. 
e, July. Stem mostly simple, terete, thick and spongy, con- 
spicuously black-warted, 2-5 feet long. Floating leaves large, 
attaining to the size of 5 in. by 34, the: uppermost more or less 
rounded-ovate, deeply cordate, on channelled petioles shorter than 
the blade; the lower ones oblong-ovate, slightly-or scarcely cor- 
date, on elongated petioles; all marked on the under side with 
very numerous, commonly impressed nerves. Submersed leaves 
rather distant, membranaceous, inconspicuously many-nerved, the 
principal ones pellucid, loosely netted veined, lanceolate with an 
and an attenuate and acuminate tip, undulate-serrate, 
short-petiolate, 5-8 in. long ; the lowest smallerand thicker, more 
oval, or spatulate, on more elongated petioles. . Stipules long, 
rather acute. Peduncles a little’thickened, commonly more than 
twice as long as the slender spike: Nutlets mah the 
back sharply tricarinate, broadly furrowed between: the k 
when dry, the middle keel prominent and slightly irregular, the 
lateral ones less acute, sides convex, sloping: to the sharply’ cari- 
nate front, which is produced at the middle. . Kxocarp thin. 
Putamen thick, hard. Seed uncinate-convolute. The floating 
leaves of this Potamogeton have probably been passed over 
as belonging to P. natans, but the two plants are very dif- 
ferent. P. natans is always characterized by its much elonga- 
ted petioles, the lower of which are so commonly destitute of 
the blade, that the species has been described as possessing lower 
leaves without b blades. It is very common with us, and near to 
P. fluitans and P. oblongus, but cannot be cohhentadie either with 
the present species or the next. The Potamogetons are typically, 
submersed plants, and their floating leaves become of importance 
in, characterizing the species, only when taken in connexion with — 
the submersed ones. ‘The floating leaves are often merely acces- _ 
sory, and their number is uncertain, the lower ones constantly 
varying in texture and'shape with the character and depth of the: ; 
- 
i ee ‘nov. ): caule simplici stipulis ampleeten- 
a ine 
reeurvis conspicue eneins undulatis petiolis longiuseulis can- 
rt, natantibus coriaceis ovato-s. oblongo-lanceolatis, su- 
s petiolis longiusculis pieces longtonbus stipulis 
