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Greenland pondweed

little aguja pondweed

Rhizomes

absent.

absent.

Cauline stems

terete, without spots, 20–50 cm;

glands white, 0.1–0.7 mm diam.

terete to slightly compressed, without spots, to 57 cm;

glands white to gold, 0.2–0.3 mm diam.

Turions

terminal or axillary, common, 4.2–8.4 cm × 1.4–2.5 mm, soft;

leaves ± 4-ranked;

outer leaves 2 per side, base without corrugations, apex acute to apiculate;

inner leaves unmodified.

unknown.

Leaves

submersed, ± spirally arranged, sessile, delicate;

stipules deliquescent to persistent, inconspicuous, convolute, free from blade, brown, not ligulate, 0.45–1.91 cm, not fibrous, not shredding at tip, apex obtuse;

blade pale to deep green, linear, not arcuate, 2.6–8.8 cm × 0.7–1.7 mm, base slightly tapering, without basal lobes, not clasping, margins entire, not crispate, apex not hoodlike, acute to apiculate, lacunae absent or present, 0–3 rows each side of midrib;

veins 7–11.

submersed, ± spirally arranged, sessile, delicate;

stipules persistent, inconspicuous, convolute, free from blade, brown, not ligulate, to 0.62 cm, not fibrous, not shredding at tip, apex obtuse;

blade green, linear, not arcuate, 3.2–7.8 cm × 0.7–1.7 mm, base slightly tapering, without basal lobes, not clasping, margins entire, not crispate, apex not hoodlike, acute, lacunae rarely absent, in 0–4 rows each side of midrib;

veins 3(–5).

Inflorescences

unbranched, emersed;

peduncles not dimorphic, terminal, erect, cylindric, 20 mm;

spikes not dimorphic, cylindric, 5 mm.

unbranched, emersed;

peduncles not dimorphic, axillary or terminal, erect, cylindric, 3.2–4.8 cm;

spike not dimorphic, capitate to cylindric, 5.5–7.5 mm.

Fruits

not laterally keeled, 2.6–2.7 × 2 mm;

beak erect, 0.3 mm;

sides without basal tubercles;

embryo with 1 full coil.

sessile, brown to yellow-green, obovoid, compressed, abaxially and laterally keeled, 2–2.2 × 1.7–1.8 mm, lateral keels without points;

beak erect, 0.5–0.6 mm;

sides with 1–3 tubercules near base;

embryo with 1 full spiral.

2n

= 26.

Potamogeton groenlandicus

Potamogeton clystocarpus

Phenology Flowering late summer. Flowering and fruiting spring–summer.
Habitat Ponds and lakes Small streams
Elevation 10–450 m (0–1500 ft) ca. 1800 m (ca. 5900 ft)
Distribution
from USDA
Greenland
[BONAP county map]
from FNA
TX
[BONAP county map]
Discussion

Of conservation concern.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Potamogeton clystocarpus is an extremely limited species known from only one canyon in west Texas.

Of conservation concern.

(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
P. alpinus, P. amplifolius, P. bicupulatus, P. clystocarpus, P. confervoides, P. crispus, P. diversifolius, P. epihydrus, P. floridanus, P. foliosus, P. friesii, P. gramineus, P. hillii, P. illinoensis, P. natans, P. nodosus, P. oakesianus, P. oblongus, P. obtusifolius, P. ogdenii, P. perfoliatus, P. praelongus, P. pulcher, P. pusillus, P. richardsonii, P. robbinsii, P. spirillus, P. strictifolius, P. subsibiricus, P. tennesseensis, P. vaseyi, P. zosteriformis
P. alpinus, P. amplifolius, P. bicupulatus, P. confervoides, P. crispus, P. diversifolius, P. epihydrus, P. floridanus, P. foliosus, P. friesii, P. gramineus, P. groenlandicus, P. hillii, P. illinoensis, P. natans, P. nodosus, P. oakesianus, P. oblongus, P. obtusifolius, P. ogdenii, P. perfoliatus, P. praelongus, P. pulcher, P. pusillus, P. richardsonii, P. robbinsii, P. spirillus, P. strictifolius, P. subsibiricus, P. tennesseensis, P. vaseyi, P. zosteriformis
Synonyms P. pusillus subsp. groenlandicus
Name authority Hagström: Kongl. Svenska Vetenskapsakademiens Handlingar n.s. 55(5): 127. (1916) Fernald: Memoirs of the american academy of arts and science n.s. 17:79, plates 15, 30, fig. 5. (1932)
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