Potamogeton alpinus |
|
---|---|
northern pondweed, reddish pondweed |
|
Stems | terete; to 200 cm; nodal glands absent. |
Leaves | submersed and floating or submersed only. |
Floating leaves | elliptic or oblanceolate to obovate or oblonglinear, 40–70(100) × 10–25(40)mm; reddish green; base gradually tapering to petiole; tip obtuse or acute; veins (7)9–13(15); petioles 0–12 mm. |
Submersed leaves | sessile, attached to stem nodes, not attached to stipules; stipules (12)15–25(40)mm; tip blunt; blades oblong-linear to linear-lanceolate, 45–180(250) × 5–20 mm; base rounded to cuneate; margins entire; tip obtuse or acute; lacunae in 0–6 rows on each side of midvein; veins 7–9. |
Inflorescences | emersed; spikes cylindric, 10–35 mm; peduncles terminal or axillary; erect, 30– 100(160)mm. |
Fruits | pedicellate, obovoid; turgid; (2.5)3–3.5 × (1.7)2–2.4 mm, dorsally keeled, laterally keeled or not; beaks dorsally curved, 0.5–0.9 mm. |
Potamogeton alpinus |
|
Distribution | |
Discussion | Ponds, lakes, and slow-moving streams. 1200–2200m. BR, BW, Casc. CA, ID, NV, WA; north to British Columbia, east to Greenland; Eurasia. Native. Potamogeton alpinus is often red when fresh. This species hybridizes with P. nodosus, P. gramineus, and P. praelongus. |
Source | Flora of Oregon, volume 1, page 496 Nick Otting, Richard Brainerd, Barbara Wilson |
Sibling taxa | |
Synonyms | Potamogeton alpinus ssp. tenuifolius, Potamogeton alpinus var. subellipticus, Potamogeton alpinus var. tenuifolius |
Web links |
|