OregonFlora: Juncus effusus vs. Juncus orthophyllus

	Juncus effusus	Juncus orthophyllus
	pasture rush, soft rush	straight-leaved rush
Habit	Plants perennial, 50–150 cm tall, cespitose; fruiting stems stout, usually 2–4.9 mm diameter above distal sheath; fresh upper stems shiny, smooth, dried stems with (12)18–26(32) weak low ridges, slender and relatively inconspicuous, visible on one side when dried, dried ridges capped with low dull cells (at 10×).	Plants perennial, 20–40 cm tall, rhizomatous.
Leaves	lacking blades; distal sheaths dull or shiny; smooth or papillose; apex symmetrical or asymmetrical; thin or thickened, winged or not.	flat; grass-like; auricles absent or inconspicuous, usually acute, 0–0.6 mm.
Inflorescences	dense or open; inflorescence bracts not swollen; erect in fruit.	3–12 clusters or head-like clusters; clusters 4–10-flowered.
Flowers	tepals 6, usually green to pale brown (dark brown-striped); stamens 3; filaments 0.4–0.7 mm; anthers 0.4–0.7 mm; styles 0–0.4 mm.	tepals 6, 5–6 × 1–1.4 mm; greenish brown, brown to dark brown, papillose; stamens 6; filaments 0.4–0.8(1) mm; anthers 1.6– 2.8 mm; styles 1.3–2.5 mm.
Capsules	1.6–2.5 mm; shorter than the tepals; light to dark brown; apices obtuse to acute (notched), 1-chambered.	oblong-ovoid, obtuse or truncate; shorter than the tepals, brown, 3-chambered.
Seeds	0.4–0.5 × 0.2 mm, reticulate, apiculate.	0.5–0.7 × 0.2–0.25 mm, reticulate, apiculate; tails less than 0.2 mm.
2n		=40.

	Juncus effusus	Juncus orthophyllus
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	The various subspecies include two introductions that often grow mingled with our native plants; the species can dominate wet pastures with heavy grazing. 9 subspecies; 3 subspecies in Oregon.	Floodplains, wet meadows, marshes, wet prairie, springs, ditches, serpentine wetlands. 300–1900m. BR, BW, Casc, Col, ECas, Owy, Sisk, WV. CA, NV, ID, WA; east to MT. Native. This species is often confused with J. longistylis, which has prominent long auricles; J. orthophyllus auricles are inconspicuous or absent. Many reports from the southern Cascades are misidentifications of J. howellii, which grows at higher elevations and has more elongated tails on the seeds.
Source	Flora of Oregon, volume 1, page 276 Peter Zika	Flora of Oregon, volume 1, page 282 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. ensifolius, 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	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, 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. 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
Subordinate taxa	J. effusus ssp. effusus, J. effusus ssp. pacificus, J. effusus ssp. solutus
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	Local floras: 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 orthophyllus

pasture rush, soft rush

straight-leaved rush

Habit

Plants perennial, 50–150 cm tall, cespitose; fruiting stems stout, usually 2–4.9 mm diameter above distal sheath; fresh upper stems shiny, smooth, dried stems with (12)18–26(32) weak low ridges, slender and relatively inconspicuous, visible on one side when dried, dried ridges capped with low dull cells (at 10×).

Plants perennial, 20–40 cm tall, rhizomatous.

Leaves

lacking blades;

distal sheaths dull or shiny; smooth or papillose;

apex symmetrical or asymmetrical; thin or thickened, winged or not.

flat; grass-like;

auricles absent or inconspicuous, usually acute, 0–0.6 mm.

Inflorescences

dense or open;

inflorescence bracts not swollen; erect in fruit.

3–12 clusters or head-like clusters; clusters 4–10-flowered.

Flowers

tepals 6, usually green to pale brown (dark brown-striped);

stamens 3;

filaments 0.4–0.7 mm;

anthers 0.4–0.7 mm;

styles 0–0.4 mm.

tepals 6, 5–6 × 1–1.4 mm; greenish brown, brown to dark brown, papillose;

stamens 6;

filaments 0.4–0.8(1) mm;

anthers 1.6– 2.8 mm;

styles 1.3–2.5 mm.

Capsules

1.6–2.5 mm; shorter than the tepals; light to dark brown;

apices obtuse to acute (notched), 1-chambered.

oblong-ovoid, obtuse or truncate; shorter than the tepals, brown, 3-chambered.

Seeds

0.4–0.5 × 0.2 mm, reticulate, apiculate.

0.5–0.7 × 0.2–0.25 mm, reticulate, apiculate; tails less than 0.2 mm.

=40.

Juncus effusus

Juncus orthophyllus

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

The various subspecies include two introductions that often grow mingled with our native plants; the species can dominate wet pastures with heavy grazing. 9 subspecies; 3 subspecies in Oregon.

Floodplains, wet meadows, marshes, wet prairie, springs, ditches, serpentine wetlands. 300–1900m. BR, BW, Casc, Col, ECas, Owy, Sisk, WV. CA, NV, ID, WA; east to MT. Native.

This species is often confused with J. longistylis, which has prominent long auricles; J. orthophyllus auricles are inconspicuous or absent. Many reports from the southern Cascades are misidentifications of J. howellii, which grows at higher elevations and has more elongated tails on the seeds.

Source

Flora of Oregon, volume 1, page 276
Peter Zika

Flora of Oregon, volume 1, page 282
Peter Zika

Sibling taxa