Species: Eleocharis elliptica Kunth

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Eleocharis elliptica Kunth

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TAXONOMY

Family:

Cyperaceae

Genus:

Eleocharis

Species Synonyms:

Eleocharis tenuis var. borealis (Svens.) Gleason
Eleocharis capitata var. borealis Svens.

Common Names:

slim spikerush
slender spikerush
elliptic spikerush

DISTRIBUTION

Canada:

southern British Columbia – Alberta – Saskatchewan – Manitoba – Quebec – Newfoundland – Nova Scotia

Saskatchewan:

southern Saskatchewan; Candle Lake – Carrot River – Welby

Ecoregion:

Moist Mixed Grassland, Aspen Parkland, Boreal Transition, Mid-Boreal Upland

HABITAT

Saskatchewan:

wet open or treed bogs and fens

Associated Species:

Carex capillaris, Carex lasiocarpa, Carex limosa, Carex livida, Carex vaginata, Galium trifidum, Juncus alpinoarticulatus ssp. nodulosus, Lobelia kalmii, Parnassia glauca, Rubus arcticus ssp. acaulis, Triglochin maritima, Triglochin palustre

RARITY STATUS

Provincial Status According
to Harms (2003):

Threatened

Nature Conservancy Status:

G5 S2

Saskatchewan Species at
Risk Status:

None

COSEWIC Status:

None

Eleocharis elliptica is threatened in Saskatchewan because it is rare or uncommon and most local populations are small. No immediate threats are known for this species.

SPECIES DESCRIPTION

Height:

5 – 90 cm

Roots:

rhizomes evident, 0.5 – 2.5 mm thick; scales persistent, sometimes decaying to coarse fibres, membranous to papery

Culms:

perennial, mat-forming, to 3 times as wide as thick, subterete, sometimes compressed, 5 – 10-ridged

Leaves:

blade bearing leaves absent; lower sheaths persistent, dark red near top, green to stramineus or red near base, papery to membranous, apex reddish-brown, occasionally toothed

Inflorescence:

spikelet terminal, solitary, erect

Spikelets:

3 – 8 mm long, ovoid; floral scales 10 – 30, spreading in fruit, 5 – 7 per mm of rachilla, apex rounded to obtuse, medium to very dark brown, midrib pale

Flowers:

perfect; perianth absent or rarely 1 – 3, about half of achene length, spinulose; stamens 3, anthers orange-brown; styles 3-cleft

Achenes:

persistent after scales fall off, trigonous, may be compressed, lemon yellow or dark yellow, orange or medium brown, rarely greenish, honeycomb reticulate; tubercles short, brown to whitish, greatly depressed

ELEOCHARIS KEY FOR SPECIES FOUND IN SASKATCHEWAN

1 Achenes with 9 – 13 longitudinal rows of horizontal ridges between prominent longitudinal ridges and achene angles; spikelets with proximal scale always subtending a flower; culms to 1.5 mm wide	E. acicularis
1 Achenes without long rows of horizontal ridges; proximal scale subtending a flower or empty; culms to 5 mm wide	2

2 Tubercle conical, confluent with achene; stigmas 3	3
2 Large shrub; leaflets lobed, less than 3 cm long; fruits red and hairy	4

3 Spikelets to 3 mm long, internodes equal in thickness and length throughout the spikelet; scales 5 – 500 per spikelet, green or pale brown; stems < 10 cm tall; rhizome lacking a bulb	E. parvula
3 Spikelets to 7 mm long, proximal internodes thicker and shorter than internodes in the middle of the spikelet; scales 4 – 12 per spikelet, tinged with purple or brown; stems to 40 cm tall; rhizomes bulbous	E. quinquefolia

4 Styles 2-fid; achenes biconvex	5
4 Styles 3-fid; achenes trigonous	7

5 Tufted annuals, roots fibrous; achenes green, stramineus, or black; anthers 0.2 – 1 mm long	E. engelmannii
5 Perennials with rhizomes or stolons; achenes yellow to dark brown; anthers 1 – 2.5 mm long	6

6 Apex of distal leaf sheath with distinct tooth on all or some culms; base of spikelet with single empty scale nearly enclosing culm	E. erythropoda
6 Apex of distal leaf sheath without distinct tooth on all culms; base of spikelet with 2 or 3 firm, empty scales	E. palustris

7 Achenes biconvex (or < 1/3 of achenes trigonous); tufted annuals; spikelets never proliferous	E. engelmannii
7 Achenes trigonous; annuals or perennials, rhizomatous or stoloniferous; spikelets may be proliferous	8

8 Achene surface honey-comb reticulate; tubercle broader than high; culms to 90 cm tall	E. elliptica
8 Achene surface minutely wrinkled or roughened but not reticulate; tubercle longer than broad; culms to 40 cm tall	9

9 Spikelets < 5 mm long; culms 4-angled and capillary	E. nitida
9 Spikelets to greater than 1 cm long; culms flat and wiry	E. compressa