Potamogeton zosteriformis Fernald

  • Authority

    Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

  • Family

    Potamogetonaceae

  • Scientific Name

    Potamogeton zosteriformis Fernald

  • Description

    Species Description - Stems elongate, freely branched, strongly compressed, 1–3 mm wide, mostly without nodal glands; rhizome scarcely developed; lvs all submersed, linear, 1–2 dm × 2–5 mm, acute or cuspidate, scarcely narrowed at base, with 1–3 main veins and numerous (to 35) very fine ones; stipular sheaths axillary, free, rather firm, 1–2 cm, obtuse to acuminate; winter-buds commonly produced, 4–7.5 cm, their lvs not strongly differentiated; peduncles stout, 2–5 cm, often curved; spike cylindric, 1.5–2.5 cm, with 7–11 whorls of fls; achenes broadly elliptic-ovoid, 4–4.5 mm, with a sharp but narrow, slightly dentate dorsal keel; 2n=52. Ponds and slow streams; Que. and N.B. to B.C., s. to Va., Ind., Io., and Calif. (P. compressus and P. zosterifolius, misapplied) A putative hybrid with no. 9 [Potamogeton strictifolius A. Benn] is P. ×haynesii Hellq. (P. longiligulatus, misapplied)

  • Common Names

    flatstem-pondweed