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| Isoetes lacustris L. | Species Image Gallery (opens in a new window) |
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| TAXONOMY | |||||||||
| Family: | Isoetaceae | ||||||||
| Genus: | Isoetes | ||||||||
| Species Synonyms: | Isoetes hieroglyphica A.A. Eat. Isoetes macrospora Durieu |
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| Common Names: | lake quillwort large-spored quillwort |
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| DISTRIBUTION | |||||||||
| Canada: | northern Saskatchewan, southern Ontario – Labrador – Newfoundland – Nova Scotia | ||||||||
| Saskatchewan: | northern Saskatchewan; Lake Athabasca – Wollaston Lake | ||||||||
| Ecoregion: | Tazin Lake Upland, Athabasca Plain | ||||||||
| HABITAT | |||||||||
| Saskatchewan: | submersed lake-bottom aquatics | ||||||||
| Associated species: | Lobelia dortmanna, Sparganium angustifolium | ||||||||
| RARITY STATUS | |||||||||
| Provincial
Status According to Harms (2003): |
Endangered |
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| Nature Conservancy Status: | G5 S1 |
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| Saskatchewan
Species at Risk Status: |
None |
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| COSEWIC Status: | None |
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| Isoetes lacustris is endangered in Saskatchewan because it is rare and regionally restricted to the northern part of the province. In addition, this species is difficult to separate from its common relative. No immediate threats are known at the present time. | |||||||||
| SPECIES DESCRIPTION | |||||||||
| Growth Habit: | completely submersed | ||||||||
| Roots: | 2-lobed, nearly globose to fusiform, corky | ||||||||
| Stems: | absent | ||||||||
| Leaves: | several to many, erect to spreading, straight to recurved, 1 – 20 cm long, lacking stomata; ligule 1 – 6 mm long, deltate | ||||||||
| Sporangia: | contain megaspores and microspores, usually in alternating cycles of leaf bases, in a pit at leaf base, 3 – 15 mm diameter, ovoid to elliptic or oblong, walls unpigmented or brown | ||||||||
| Megaspores: | globose, 300 - 700 µm diameter, trilete, with equatorial ridge and 3 converging proximal ridges, white, gray or black, surface irregularly jagged ridged, ridges with sharp peaks | ||||||||
| Microspores: | reniform, mostly 20 – 50 µm, monolete, grayish or brownish, smooth | ||||||||
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