Species: Juncus albescens (Lange) Fern.

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Juncus albescens (Lange) Fern.

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TAXONOMY

Family:

Juncaceae

Genus:

Juncus

Species Synonyms:

Juncus triglumis ssp. albescens (Lange) Hultén
Juncus triglumis var. albescens Lange

Common Names:

northern white rush
pale three-flowered rush

DISTRIBUTION

Canada:

Yukon Territory – Mackenzie District – Victoria Island – Baffin Island, south to southeastern British Columbia – southwestern Alberta – northern Saskatchewan – northeastern Manitoba – northern Ontario – Ungava – Labrador – eastern Quebec

Saskatchewan:

northern Saskatchewan; Lake Athabasca – Hasbala Lake

Ecoregion:

Athabasca Plain, Selwyn Lake Upland

HABITAT

Saskatchewan:

muskegs, drainage channels, and tundra boulder fields

Associated Species:

Betula nana, Dasiphora floribunda, Picea mariana

RARITY STATUS

Provincial Status According
to Harms (2003):

Endangered

Nature Conservancy Status:

G5 S1

Saskatchewan Species at
Risk Status:

None

COSEWIC Status:

None

Juncus albescens 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.

SPECIES DESCRIPTION

Height:

3 – 35 cm

Roots:

rhizomatous

Stems:

perennial, stems 1 – 8, caespitose, may form tussocks, very slender

Leaves:

basal leaves 2 – 4, blade deeply channelled, 2 – 10 cm long, mostly shorter than culms; auricles prolonged, rounded, scarious

Inflorescence:

head solitary, 2 – 3-flowered, terminal; primary bracts brownish, about equal to the inflorescence, apex awned or acuminate

Flowers:

tepals 3 – 5 mm long, outer and inner series nearly equal, oblong, pale brown to darker, whitish, or pinkish; stamens 6; ovary superior, stigmas 3

Fruits:

capsules barely exserted from perianth, 3 – 5 mm long, apex nearly truncate, 3-locular, tan; seeds tan or darker, fusiform, with white tails shorter than the body

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 lower stem or leaves all 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 nodulose-septate (divided by cross-partitions), terete, or if flattened, strongly equitant	4
3 Leaves not nodulose-septate, terete or if flattened, not equitant	12

4 Leaves strongly flattened and equitant	5
4 Leaves terete or slightly compressed	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; auricles lacking	J. ensifolius
6 Stamens 6; auricles 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 tubers	9

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

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	13
12 Each flower subtended only by the single bractlet at the base of the very short pedicel	19

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

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

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

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

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

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

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

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