Coefficient of Conservatism:
Coefficient of Wetness:
Potamogeton filiformis, Potamogeton vaginatus
Potamogeton filiformis of Michigan Flora.
Lakes (including the Great Lakes) and rivers, at depths up to at least 1.2 m, but apparently fruiting best in shallow water over a sandy bottom. Represented in Michigan by two subspecies, which each occur ± throughout. The common subsp. filiformis is a compact plant typically 10–30 cm long with narrow leaves mostly not over 0.5 mm broad and stipular sheaths tightly clasping (< 2 mm wide) throughout; the uncommon subsp. occidentalis (J. W. Robbins) R. R. Haynes, Les, & M. Král is a larger plant ca. 20–100 cm long with leaves up to 1.2 (–2.5) mm wide and stipular sheaths loose, those at the base of the stem (2–) 2.5–5 mm wide (Potamogeton vaginatus of Michigan Flora). Some specimens treated as Potamogeton vaginatus in Michigan Flora are also the hybrid Stuckenia ×suecica (K. Richt.) Holub (S. filiformis × S. pectinata), which may be overlooked in our flora; see Kaplan (2008).