Juncus castaneus ssp. castaneus Sm.
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Family: Juncaceae
Genus: Juncus
Species Synonyms: none
Common Names: chestnut rush
Canada: Yukon Territory – Mackenzie District – Victoria Island – Baffin Island, south to southwestern British – southwestern Alberta – northeastern Saskatchewan – Manitoba – northern Ontario – Quebec – Labrador
Saskatchewan: northern Saskatchewan; Hasbala Lake
Ecoregion: Selwyn Lake Upland
Saskatchewan: treed bogs, tundra, alpine meadows, gravel beaches, clay banks
Provincial Status According
to Harms (2003):
Nature Conservancy Status:
Saskatchewan Species at
Risk Status:
Chestnut rush is endangered in Saskatchewan because it is rare and regionally restricted to the northern part of the province. No immediate threats are known at the present time.
Height: 10 – 40 cm
Roots: rhizome runner-like
Stems: perennial, solitary, stiffly erect
Leaves: some on the stem, 3 – 5, blades channelled, to 20 cm long, 1 – 2 mm wide; ear-like lobes at the base of the leaf rounded
Inflorescence: heads 1 – 3, the lowest sessile or nearly so, the upper stalked, 2 – 10-flowered; stalks < 1.5 cm long; primary bracts somewhat inflated, usually surpassing inflorescence, 2 – 8 cm long, erect
Flowers: small bracts at the base of each flower absent; tepals 4.5 – 6.5 mm long, inner series slightly shorter than the outer, lance-shaped, chestnut brown; stamens 6
Fruits: capsules exceeding the perianth, 6 – 9 mm long, narrowed to a beak, 3-locular, chestnut brown; seeds pale yellow, tails 0.8 – 11 mm long
1 Inflorescence appearing lateral; leaves all basal
1 Inflorescence appearing terminal; may have at least one blade-bearing leaf on the lower stem or all leaves 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 divided by cross-partitions, rounded, or if flattened, bases overlapping and blades appearing oriented with the edge towards the stem
3 Leaves not divided by cross-partitions, rounded or if flattened, not appearing oriented with the edge towards the stem
4 Leaves strongly flattened and bases overlapping and blades appearing oriented with the edge towards the stem
4 Leaves rounded or slightly flattened
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; 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
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 swellings
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 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
12 Each flower subtended only by the single bractlet at the base of the very short stalk
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 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 Sepals erect, closely appressed to the capsule
J. vaseyi
15 Sepals spreading to ascending, not closely appressed to the capsule
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 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 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 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 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