Juncus interior var. interior Wieg.
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Family: Juncaceae
Genus: Juncus
Species Synonyms: Juncus tenuis var. uniflorus auct. p.p., non Farw.
Common Names: inland rush
Canada: southern Alberta – southern Saskatchewan – western Ontario
Saskatchewan: southern Saskatchewan; Swift Current – Loreburn
Ecoregion: Mixed Grassland, Moist Mixed Grassland, Aspen Parkland
Saskatchewan: wet to drying mudflats, slough bottoms, shores, and field depressions
Associated species: Alopecurus aequalis, Beckmannia syzigachne, Eleocharis acicularis
Provincial Status According
to Harms (2003):
Nature Conservancy Status:
G4G5T4T5 S2
Saskatchewan Species at
Risk Status:
Juncus interior var. interior is vulnerable in Saskatchewan because it is rare or uncommon. It is somewhat regionally restricted to the southern region of the province. Local population sizes vary. No immediate threats are known at present.
Height: 20 – 60 cm
Roots: rhizome densely branching
Stems: perennial, caespitose, 1 – 10
Leaves: basal, 1 – 2, blades 5 – 15 cm long, typically shorter than culm, 1 – 2 mm wide, channelled or involute; auricles whitish or purplish tinged, scarious
Inflorescence: cyme somewhat compact to open, 1.5 – 7 cm; primary bract usually shorter than inflorescence
Flowers: bracteoles 2; tepals 3 – 6 mm long, inner and outer series equal or the outer slightly longer, apex acuminate, greenish; stamens 6, anther much shorter than the filament
Fruits: capsules 4 – 5 mm long, ellipsoid to nearly globose, 1-locular, light tan or darker; seeds tan, not tailed
1 Inflorescence appearing lateral; leaves all basal
1 Inflorescence appearing terminal; may have at least one blade-bearing leaf on lower stem or leaves all basal
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 nodulose-septate (divided by cross-partitions), terete, or if flattened, strongly equitant
3 Leaves not nodulose-septate, terete or if flattened, not equitant
4 Leaves strongly flattened and equitant
4 Leaves terete or slightly compressed
5 Styles surpassing petals; seeds with a distinct tail-like appendage
J. tracyi
5 Styles equal to petals; seeds without a tail
6 Stamens 3; auricles lacking
J. ensifolius
6 Stamens 6; auricles present
J. saximontanus
7 Flowers in dense spherical heads
7 Flowers few to many in narrower heads
8 Heads solitary; rhizomes densely matted
J. mertensianus
8 Heads solitary; rhizomes elongate and creeping, often bearing tubers
9 Tepals reddish-brown, inner tepals longer than or equal to outer tepals; leaves 1 – 2 mm thick; sheaths with yellowish auricles
J. nodosus var. nodosus
9 Tepals greenish to dull brown, inner tepals shorter than outer tepals; leaves to 5 mm thick; sheaths with hyaline auricles
J. torreyi
10 Seeds about 1 mm long, with definite white tail-like appendages
J. brevicaudatus
10 Seeds less than 0.5 mm long, apiculate but without white tails
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 pedicel
12 Each flower subtended only by the single bractlet at the base of the very short pedicel
13 Roots fibrous; dwarf species, branched near base; annuals; leaf sheaths not auricled
J. bufonius
13 Rhizomes elongate or short if culms densely tufted; plants not dwarfed or branched near the base; perennials; leaf sheaths auricled or prolonged
14 Leaf sheaths extending to about halfway up the culm
J. compressus
14 Leaf sheaths confined to base or only extending to about one third of the way up the stem
15 Sepals erect, closely appressed to the capsule
J. vaseyi
15 Sepals spreading to ascending, not closely appressed to the capsule
16 Auricles short and round; leaf blades less than half the length of the culm
J. dudleyi
16 Auricles delicate and scarious; leaf blades usually greater than half the length of the culm
17 Capsule 3-loculed, nearly equalling the perianth; inflorescence compact
J. confusus
17 Capsule 1-loculed, distinctly shorter than the perianth; inflorescence a loose panicle
18 Auricles prolonged into a membranous projection 3 – 5 mm long
J. tenuis
18 Auricles shorter, up to 2 mm long, submembranous
J. interior
19 Seeds apiculate; leaves flattened and grass-like
J. longistylus
19 Seeds with distinct white tail-like appendages; leaves terete to somewhat compressed or deeply channelled
20 Culms arising from elongate rhizomes; perianth and capsules dark brown to black
J. castaneus ssp. castaneus
20 Culms not rhizomatous, may form tussocks; perianth and capsules pale
21 Capsules to 9 mm long; heads 1 – 2; lower cauline leaves 1 – 3
J. stygius ssp. americanus
21 Capsules to 4 mm long; heads solitary; leaves all basal
J. albescens