Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
55. Potamogetonaceae, the Pondweed Family
1. Potamogeton L. -- Pondweed
8. Potamogeton friesii Rupr.
Stems compressed, mostly 0.5-1 mm wide, simple or branched, to 1-1.5
m long. Leaves all submersed, linear, 2.3-6.5 cm long, 1.2-3.2 mm wide,
5- to 7(9)-nerved, rounded to apiculate at the tip, the margin flat to eventually
revolute, tapered to the sessile base; stipules free, white and fibrous,
often shredding above, 5-20 mm long; glands present at the base of the
stipules. Winter buds common, terminal or lateral, 1.5-5 cm long; inner
leaves reduced, arranged into a fan-shaped structure; outer leaves
2-3 per side, apiculate to acute, indurate and corrugated at the base. Spikes
cylindric, 7-16 mm long; floral whorls 2-5, 1.5-5 mm apart; peduncles
slightly clavate, mostly 1.5-4(7) cm long. Fruits olive-green to brown,
ovoid to obovoid, 1.8-2.5 mm long, rounded on the back. Jun--Aug. Shallow, fresh
to brackish water of lakes and ponds; occasional from ND and e MT, s to n NE;
(Newf. to AK, s to PA, n IN, IA, NE and UT).
Previous Section -- Potamogeton foliosus Raf.
-- Leafy pondweed
Return to Family -- Potamogetonaceae - The
Next Section -- Potamogeton gramineus L. -- Variable