Potamogeton pulcher |
Potamogeton amplifolius |
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heartleaf pondweed, potamot gracieux, spotted pondweed |
big-leaf pondweed, broad-leaf pondweed, large-leaf pondweed, potamot à grandes feuilles |
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Rhizomes | present. |
present. |
Cauline stems | terete, conspicuously spotted, 8–95 cm; nodal glands absent. |
terete, often rusty spotted, 6–110 cm; nodal glands absent. |
Turions | absent. |
absent. |
Leaves | both submersed and floating, ± spirally arranged. |
both submersed and floating or floating absent, ± spirally arranged. |
Floating leaves | petioles continuous in color to apex, 1–16.5 cm; blade adaxially light to dark green, lanceolate to round-ovate, 2.5–8.5 cm × 11–44 mm, base rounded to cordate, apex acute to rounded; veins 15–21. |
petioles continuous in color to apex, 2.3–22.6 cm; blade adaxially light green, lanceolate to round elliptic, 4.3–9.2 cm × 25–38 mcm, base rounded to cordate, apex acute to rounded; veins 27–49. |
Submersed leaves | petiolate, lax; stipules deliquescent, inconspicuous, convolute, free from blade, light to dark brown, not ligulate, 0.7–1.2 cm, not fibrous, not shredding at tip, apex obtuse; petioles 0.5–4.5 cm; blade dark green, linear-lanceolate to lanceolate, often arcuate, 3.5–13.8 cm × 60–165 mm acute, base acute to rounded, without basal lobes, margins entire, crispate, apex not hoodlike, acute to obtuse, lacunae in 2–5 rows each side of midrib; veins 7–19. |
petiolate, lax; stipules persistent, conspicuous, convolute, free from blade, light brown, not ligulate, 1.5–11.7 cm, not fibrous, not shredding at tip, apex acute; petioles terete, 0.9–11.5 cm; blade light to dark green, ovate to oblanceolate, distinctly arcuate, 5–12.5 cm × 15–58 mm, base rounded to acute, without basal lobes, not clasping, margins entire, crispate, apex not hoodlike, acute to round-apiculate, lacunae absent; veins 19–49. |
Inflorescences | unbranched, emersed; peduncles not dimorphic, terminal or axillary, erect to ascending, cylindric, 3.3–9.4 cm; spikes not dimorphic, cylindric, 17–36 mm. |
unbranched, emersed; peduncles not dimorphic, terminal or axillary, erect, cylindric, 4.5–22.3 cm; spikes not dimorphic, cylindric, 34–65 mm. |
Fruits | sessile, dark green to dark brown, ovoid to obovoid, turgid, abaxially keeled, laterally ridged, 5–6.5 × 4.1–5 mm, lateral ridges without points; beak erect, 0.5 mm; embryo with 1 full spiral. |
sessile, reddish brown, obovoid, turgid, abaxially keeled, laterally ridged, 5–6.7 × 4.5–5.2 mm, lateral ridges without points; beak erect, 0.5–0.8 mm; sides without basal tubercles; embryo with full spiral. |
Chromosome number | apparently unknown not available. |
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2n | = 52. |
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Potamogeton pulcher |
Potamogeton amplifolius |
|
Phenology | Flowers summer–fall. | Flowering summer–fall. |
Habitat | Stagnant to slow-flowing waters of streams, lakes, ponds, and small rivers | Waters of lakes, ponds, streams, and rivers |
Elevation | 0–700 m (0–2300 ft) | 0–1900(–2900) m (0–6200(–9500) ft) |
Distribution |
AL; AR; CT; DE; FL; GA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WI; WV; NB; NS; PE; Ont
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AL; AR; CA; CT; GA; IA; ID; IL; IN; KS; MA; MD; ME; MI; MN; MO; MT; NC; NE; NH; NJ; NY; OH; OK; OR; PA; RI; SD; TN; VA; VT; WA; WI; WV; WY; BC; MB; NB; NF; NS; ON; QC; SK
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Discussion | Potamogeton pulcher is similar in morphology to P. amplifolius and occurs in similar habitats. Potamogeton pulcher differs from P. amplifolius by the former having lanceolate to linear-lanceolate submersed leaves with fewer than 19 veins, whereas the latter has ovate submersed leaves with more than 19 veins. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
No specimens have been seen from Kentucky or Texas, but the species is to be expected there. Potamogeton amplifolius is common throughout much of North America. Its submersed leaves are larger than those of most other species of Potamogeton, are arcuate, and have more veins than do any other species. One hybrid, Potamogeton amplifolius × P. illinoensis (= P. × scoliophyllus Hagström), has been described. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Potamogetonaceae > Potamogeton | Potamogetonaceae > Potamogeton |
Sibling taxa | ||
Name authority | Tuckerman: American Journal of Science, and Arts 45:38. (1843) | Tuckerman: American Journal of Science, and Arts ser. 2, 6:225. (1848) |
Web links |
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