OregonFlora: Juncus ensifolius

	Juncus ensifolius
	dagger-leaved rush, swordleaf rush
Habit	Plants perennial, 15–65 cm tall, rhizomatous.
Leaves	flat; iris-like, blue-green, partially septate; auricles usually absent (0.1–0.4 mm).
Inflorescences	1–12(22) clusters; clusters often head-like, 3–70-flowered.
Flowers	tepals 6, brown to often dark brown or black; stamens 3; filaments 0.6–1.1 mm; anthers 0.4–0.7 mm; styles 0.2–0.8(1) mm.
Capsules	longer than or equaling tepals, dark brown to blackish; apices obtuse or acute and abruptly tapered to short beak, 1-chambered.
Seeds	0.4–0.5(0.6) × 0.15–0.2 mm, apiculate, reticulate.

	Juncus ensifolius
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Shores, swales, springs, wet meadows, wet prairie, damp dunes, peatlands, ditches. 0–2500m. Throughout Oregon. CA, ID, NV, WA; north to Alaska, east to Saskatchewan, SD and CO, south to AZ and Mexico; Ontario and Quebec south to WI and NY; HI; northeastern Asia, Europe, New Zealand. Native. With three stamens, this species is reliably separated from J. saximontanus, which has six stamens. Rare plants with variable stamen numbers in an inflorescence may represent hybrids and need investigation.
Source	Flora of Oregon, volume 1, page 277 Peter Zika
Sibling taxa	J. acuminatus, J. anthelatus, J. articulatus, J. balticus, J. bolanderi, J. brevicaudatus, J. breweri, J. bryoides, J. bufonius, J. bulbosus, J. canadensis, J. capillaris, J. capitatus, J. compressus, J. confusus, J. conglomeratus, J. covillei, J. diffusissimus, J. drummondii, J. dudleyi, J. effusus, J. ensifolius x Juncus nevadensis, J. exiguus, J. falcatus, J. filiformis, J. gerardi, J. hemiendytus, J. hesperius, J. howellii, J. inflexus, J. interior, J. kelloggii, J. laccatus, J. lescurii, J. longistylis, J. marginatus, J. mertensianus, J. mexicanus, J. nevadensis, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. planifolius, J. ranarius, J. regelii, J. saximontanus, J. supiniformis, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. trilocularis, J. uncialis
Synonyms	Juncus ensifolius var. ensifolius, Juncus tracyi
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Juncus ensifolius

dagger-leaved rush, swordleaf rush

Habit

Plants perennial, 15–65 cm tall, rhizomatous.

Leaves

flat; iris-like, blue-green, partially septate;

auricles usually absent (0.1–0.4 mm).

Inflorescences

1–12(22) clusters; clusters often head-like, 3–70-flowered.

Flowers

tepals 6, brown to often dark brown or black;

stamens 3;

filaments 0.6–1.1 mm;

anthers 0.4–0.7 mm;

styles 0.2–0.8(1) mm.

Capsules

longer than or equaling tepals, dark brown to blackish;

apices obtuse or acute and abruptly tapered to short beak, 1-chambered.

Seeds

0.4–0.5(0.6) × 0.15–0.2 mm, apiculate, reticulate.

Juncus ensifolius

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Shores, swales, springs, wet meadows, wet prairie, damp dunes, peatlands, ditches. 0–2500m. Throughout Oregon. CA, ID, NV, WA; north to Alaska, east to Saskatchewan, SD and CO, south to AZ and Mexico; Ontario and Quebec south to WI and NY; HI; northeastern Asia, Europe, New Zealand. Native.

With three stamens, this species is reliably separated from J. saximontanus, which has six stamens. Rare plants with variable stamen numbers in an inflorescence may represent hybrids and need investigation.

Source

Flora of Oregon, volume 1, page 277
Peter Zika

Sibling taxa

J. acuminatus, J. anthelatus, J. articulatus, J. balticus, J. bolanderi, J. brevicaudatus, J. breweri, J. bryoides, J. bufonius, J. bulbosus, J. canadensis, J. capillaris, J. capitatus, J. compressus, J. confusus, J. conglomeratus, J. covillei, J. diffusissimus, J. drummondii, J. dudleyi, J. effusus, J. ensifolius x Juncus nevadensis, J. exiguus, J. falcatus, J. filiformis, J. gerardi, J. hemiendytus, J. hesperius, J. howellii, J. inflexus, J. interior, J. kelloggii, J. laccatus, J. lescurii, J. longistylis, J. marginatus, J. mertensianus, J. mexicanus, J. nevadensis, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. planifolius, J. ranarius, J. regelii, J. saximontanus, J. supiniformis, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. trilocularis, J. uncialis

Synonyms

Juncus ensifolius var. ensifolius, Juncus tracyi

Web links

Local floras: BC, CA, OR, WA
Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria
WildflowerSearch
iNaturalist (observations)
USDA Plants Database
LBJ Wildflower Center
SEINet
Plants of the World Online
Encyclopedia of Life
Wikipedia
Google Image Search

Unless otherwise noted, all data comes from OregonFlora.

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

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Juncus ensifolius

Juncus ensifolius