Species: Juncus ensifolius Wikstr.

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Juncus ensifolius Wikstr.

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TAXONOMY

Family:

Juncaceae

Genus:

Juncus

Species Synonyms:

Juncus ensifolius var. major Hook.
Juncus xiphioides var. triandrus Engelm

Common Names:

dagger rush
swordleaf rush
three-stamened rush
equitant-leaved rush

DISTRIBUTION

Canada:

Yukon Territory – British Columbia, southeastern Alberta – south western Saskatchewan, Ontario – Quebec

Saskatchewan:

southern and central Saskatchewan; Cypress Hills, Duck Lake

Ecoregion:

Cypress Upland, Mid-Boreal Upland

HABITAT

Saskatchewan:

shores and springy areas

RARITY STATUS

Provincial Status According
to Harms (2003):

Threatened

Nature Conservancy Status:

G5 S2

Saskatchewan Species at
Risk Status:

None

COSEWIC Status:

None

Dagger rush is threatened in Saskatchewan because it is rare. It is located in two regions of the province, but its range does not seem to be continuous. Local population sizes vary. No immediate threats are known for this species.

SPECIES DESCRIPTION

Height:

20 – 60 cm

Roots:

rhizome 2 – 3 mm in diameter

Stems:

perennial, erect, flattened and two-edged

Leaves:

basal leaves 1 – 3, stem leaves 2 – 6, straw-coloured, blade 2 – 25 cm long, 1 – 6 mm wide; ear-like lobes absent

Inflorescence:

branched or unbranched clusters of 2 – 50 heads or head solitary, branches erect or ascending; heads 3 – 70-flowered, 7 – 11 mm diameter; primary bract erect

Flowers:

tepals of different lengths, the inner slightly shorter than the outer, green to brown or reddish-brown, tip sharp; stamens 3, anthers half as long as filament

Fruits:

capsules 2.4 – 4.3 mm long, equal to or slightly longer than the tepals, with a sharp abrupt tip, 1-locular, chestnut to dark brown; seeds elliptic to inversely egg-shaped, < 1 mm long, occasionally with a tail

JUNCUS KEY FOR SPECIES FOUND IN SASKATCHEWAN

1 Inflorescence appearing lateral; leaves all basal	2
1 Inflorescence appearing terminal; may have at least one blade-bearing leaf on the lower stem or all leaves basal	3

2 Bract stout, much shorter than stem; perianth parts usually darker brown; anthers commonly much longer than their filaments	J. balticus
2 Bract slender, as long as or longer than stem; perianth parts greenish to light brown; anthers commonly shorter than or equal to their filaments	J. filiformis

3 Leaves divided by cross-partitions, rounded, or if flattened, bases overlapping and blades appearing oriented with the edge towards the stem	4
3 Leaves not divided by cross-partitions, rounded or if flattened, not appearing oriented with the edge towards the stem	12

4 Leaves strongly flattened and bases overlapping and blades appearing oriented with the edge towards the stem	5
4 Leaves rounded or slightly flattened	7

5 Styles surpassing petals; seeds with a distinct tail-like appendage	J. tracyi
5 Styles equal to petals; seeds without a tail	6

6 Stamens 3; ear-like lobes at the base of the leaf lacking	J. ensifolius
6 Stamens 6; ear-like lobes at the base of the leaf present	J. saximontanus

7 Flowers in dense spherical heads	8
7 Flowers few to many in narrower heads	10

8 Heads solitary; rhizomes densely matted	J. mertensianus
8 Heads solitary; rhizomes elongate and creeping, often bearing swellings	9

9 Tepals reddish-brown, inner tepals longer than or equal to outer tepals; leaves 1 – 2 mm thick; sheaths with yellowish ear-like lobes	J. nodosus var. nodosus
9 Tepals greenish to dull brown, inner tepals shorter than outer tepals; leaves to 5 mm thick; sheaths with membranous ear-like lobes	J. torreyi

10 Seeds about 1 mm long, with definite white tail-like appendages	J. brevicaudatus
10 Seeds less than 0.5 mm long, sharply pointed but without white tails	11

11 Anthers shorter than or equalling their filaments; perianth segments obtuse; capsule exceeding the perianth	J. alpinoarticulatus ssp. nodulosus
11 Anthers distinctly longer than their filaments; perianth segments acute; capsule shorter than or equal to the perianth	J. nevadensis

12 Each flower inserted singly on the branches of the inflorescences and subtended by a pair of small bractlets in addition to the bractlet at the base of the flower stalk	13
12 Each flower subtended only by the single bractlet at the base of the very short stalk	19

13 Roots fibrous; dwarf species, branched near base; annuals; leaf sheaths without ear-like lobes	J. bufonius
13 Rhizomes elongate or short if stem densely tufted; plants not dwarfed or branched near the base; perennials; leaf sheaths with ear-like lobes or prolonged	14

14 Leaf sheaths extending to about halfway up the stem	J. compressus
14 Leaf sheaths confined to base or only extending to about one third of the way up the stem	15

15 Sepals erect, closely appressed to the capsule	J. vaseyi
15 Sepals spreading to ascending, not closely appressed to the capsule	16

16 Ear-like lobes at the base of the leaf short and round; leaf blades less than half the length of the stem	J. dudleyi
16 Ear-like lobes at the base of the leaf delicate and membranous; leaf blades usually greater than half the length of the stem	17

17 Capsule 3-loculed, nearly equalling the perianth; inflorescence compact	J. confusus
17 Capsule 1-loculed, distinctly shorter than the perianth; inflorescence a loose, branched inflorescence	18

18 Ear-like lobes at the base of the leaf prolonged into a membranous projection 3 – 5 mm long	J. tenuis
18 Ear-like lobes at the base of the leaf shorter, up to 2 mm long, nearly membranous	J. interior

19 Seeds with a sharp point; leaves flattened and grass-like	J. longistylus
19 Seeds with distinct white tail-like appendages; leaves rounded to somewhat flattened or deeply channelled	20

20 Stems arising from elongate rhizomes; perianth and capsules dark brown to black	J. castaneus ssp. castaneus
20 Stems not rhizomatous, may form clumps; perianth and capsules pale	21

21 Capsules to 9 mm long; heads 1 – 2; lower stem leaves 1 – 3	J. stygius ssp. americanus
21 Capsules to 4 mm long; heads solitary; leaves all basal	J. albescens