Species: Sparganium hyperboreum Laestad.

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Sparganium hyperboreum Laestad.

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TAXONOMY

Family:

Sparganiaceae

Genus:

Sparganium

Species Synonyms:

Sparganium submuticum (Hartm.) Hartm.
Sparganium williamsii Rydb.

Common Names:

northern bur-reed

DISTRIBUTION

Canada:

Yukon – Mackenzie District – Keewatin District – Ungava – Labrador, south to west-central British Columbia, northwestern Saskatchewan, northeastern Manitoba, northwestern Ontario, eastern Quebec – Newfoundland

Saskatchewan:

northwestern Saskatchewan; Lake Athabasca

Ecoregion:

Tazin Lake Upland

HABITAT

Saskatchewan:

emergent shallow-water aquatics at sedge-marshy streamlet borders

Canada:

ponds and lakes

RARITY STATUS

Provincial Status According
to Harms (2003):

Endangered

Nature Conservancy Status:

G5 S2

Saskatchewan Species at
Risk Status:

None

COSEWIC Status:

None

Sparganium hyperboreum is endangered because of extreme rarity in Saskatchewan. It is regionally restricted to the northwest corner of the province and is almost always locally sparse. Immediate or probable threats have been identified.

SPECIES DESCRIPTION

Height:

10 – 30 cm

Roots:

fibrous

Stems:

slender, grass-like, weak

Leaves:

usually floating, 10 – 50 cm long, 2 – 4 mm wide, linear, flat

Inflorescence:

staminate heads 1, terminal, contiguous with uppermost pistillate head; pistillate heads 1 – 4, axillary, sessile or lower ones short-peduncled, about 1 cm broad at maturity; rachis unbranched, flexuous; bracts ascending, lower bracts inflated near base

Flowers:

tepals without dark spot at apex, margin erose; stigmas 1

Fruits:

achenes 1.5 – 2.5 mm, brown or yellowish, dull, ribbed, beakless or nearly so

SPARGANIUM KEY FOR SPECIES FOUND IN SASKATCHEWAN

1 Stigmas 2; achenes sessile, to about 8 mm thick, broadly obpyramidal; leaves to 12 mm wide	S. eurycarpum
1 Stigmas 1; achenes more or less stipitate, to about 3 mm thick, ellipsoid; leaves 2 – 20 mm wide	2

2 Achene beakless or beak less than 1.5 mm; staminate heads 1	3
2 Achene conspicuously beaked, up to 6 mm long; staminate heads usually 2 or more	5

3 Achenes beakless; leaves 1 – 5 mm wide, often yellow	S. hyperboreum
3 Achenes with beaks up to 1.5 mm long; leaves 2 – 20 mm wide, green	4

4 Terminal staminate head remote; leaves thin, 2 – 8 mm wide	S. natans
4 Terminal staminate head not remote from pistillate heads; leaves thicker, to 2 cm wide	S. glomeratum

5 Sepals inserted on the middle of the stipe and rarely reaching middle of achene	S. fluctuans
5 Sepals inserted at the top of the stipe and commonly exceeding the middle of achene	6

6 Beak of achene as long as the body; sepals appressed; leaves erect or ascending	S. chlorocarpum
6 Beak of achene shorter than body; sepals ascending or spreading; leaves submersed or floating	7

7 Leaves 2 – 5 mm wide, rounded on the back; pistillate heads 1 – 2 cm broad	S. angustifolium
7 Leaves to 5 – 12 mm wide, flat and ribbon-like; pistillate heads > 2 cm broad	S. multipedunculatum