OregonFlora: Juncus hesperius

	Juncus hesperius
	bog rush, coast rush
Habit	Plants perennial, 30–100 cm tall, cespitose, fresh stems slightly dull, slightly ridged, slender, usually 0.8–1.9 mm diameter above distal sheath, with 5–14(18) strong ridges visible when dried.
Leaves	lacking blades; distal sheaths 4–20 cm, green (fresh) to pale or medium brown (dried); dull to slightly shiny, papillose; apex usually strongly asymmetrical on fruiting stems; thin, with broad membranous wings, flattened and lacking raised rims.
Inflorescences	a loose to dense cluster; branches usually visible; inflorescence bracts not swollen; erect.
Flowers	tepals 6, dark brown-striped; stamens 3; filaments 0.5–0.6 mm; anthers 0.5–0.8 mm; styles 0.05–0.1 mm.
Capsules	2–2.7 mm; shorter than the tepals, brown to dark brown; apex acute to notched or obtuse, 1-chambered.
Seeds	0.4–0.5 × 0.2–0.25 mm, reticulate, apiculate.

	Juncus hesperius
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Shores, springs, swales, peatlands, wet pastures, cranberry farms, ditches. 0–800m. CR, Est, WV. CA, WA; north to British Columbia. Native. This species rarely hybridizes with J. laccatus. Montane J. exiguus has a symmetrical sheath apex and smooth sheath, differing from the more coastal J. hesperius, which has an asymmetrical sheath apex and papillose sheaths.
Source	Flora of Oregon, volume 1, page 278 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, J. ensifolius x Juncus nevadensis, J. exiguus, J. falcatus, J. filiformis, J. gerardi, J. hemiendytus, 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
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Juncus hesperius

bog rush, coast rush

Habit

Plants perennial, 30–100 cm tall, cespitose, fresh stems slightly dull, slightly ridged, slender, usually 0.8–1.9 mm diameter above distal sheath, with 5–14(18) strong ridges visible when dried.

Leaves

lacking blades;

distal sheaths 4–20 cm, green (fresh) to pale or medium brown (dried); dull to slightly shiny, papillose;

apex usually strongly asymmetrical on fruiting stems; thin, with broad membranous wings, flattened and lacking raised rims.

Inflorescences

a loose to dense cluster;

branches usually visible;

inflorescence bracts not swollen; erect.

Flowers

tepals 6, dark brown-striped;

stamens 3;

filaments 0.5–0.6 mm;

anthers 0.5–0.8 mm;

styles 0.05–0.1 mm.

Capsules

2–2.7 mm; shorter than the tepals, brown to dark brown;

apex acute to notched or obtuse, 1-chambered.

Seeds

0.4–0.5 × 0.2–0.25 mm, reticulate, apiculate.

Juncus hesperius

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Shores, springs, swales, peatlands, wet pastures, cranberry farms, ditches. 0–800m. CR, Est, WV. CA, WA; north to British Columbia. Native.

This species rarely hybridizes with J. laccatus. Montane J. exiguus has a symmetrical sheath apex and smooth sheath, differing from the more coastal J. hesperius, which has an asymmetrical sheath apex and papillose sheaths.

Source

Flora of Oregon, volume 1, page 278
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, J. ensifolius x Juncus nevadensis, J. exiguus, J. falcatus, J. filiformis, J. gerardi, J. hemiendytus, 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

Web links

Local floras: BC, CA, OR, WA
Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria
WildflowerSearch
iNaturalist (observations)
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: OregonFlora, UW Burke Herbarium

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Juncus hesperius

Juncus hesperius