FNA: Juncus acutus vs. Juncus inflexus

	Juncus acutus	Juncus inflexus
	sharp rush, spiny rush	blue rush, European blue rush, European Meadow rush
Habit		Herbs, perennial, cespitose, stooling, 4–10 (–12) dm.
Rhizomes		3–5 mm diam.
Culms		terete, 1.5–3 mm diam.
Cataphylls		several.
Leaves		blade absent.
Inflorescences		many flowered, open, 2–7 cm; primary bract terete, 10–25 cm.
Flowers		pedicellate; bracteoles ovate; tepals straw-colored to reddish brown, lanceolate, 2.7–3.5 mm, margins scarious; inner series loosely subtending capsule at maturity, shorter; stamens 6, filaments 0.8–1.5 mm, anthers 0.8–1 mm; style 0.3 mm.
Capsules		reddish brown to chestnut brown, 3-locular, 3-gonous-ovoid to widely ellipsoid, 3–4 mm, exceeding perianth.
Seeds		amber, obovoid, 0.3–0.5 mm, not tailed.
2n		= 20, 38, 40.

	Juncus acutus	Juncus inflexus
Phenology		Flowering and fruiting summer.
Habitat		Wet soils along streams, ditches, and on wet, sandy and peaty hillsides
Distribution	AZ; CA; NV; South America; Mexico (Baja Calif); South Africa; Atlantic Islands [WildflowerSearch map] [BONAP county map]	MI; NY; PA; VA; ON; Europe; Asia; Africa [Introduced in North America] [BONAP county map]
Discussion	Subspecies 2 (1 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 22, p. 237.	FNA vol. 22.
Parent taxa	Juncaceae > Juncus > subg. Juncus	Juncaceae > Juncus > subg. Genuini
Sibling taxa	J. acuminatus, J. acutiflorus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. cooperi, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. inflexus, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. polycephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides	J. acuminatus, J. acutiflorus, J. acutus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. cooperi, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. polycephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides
Subordinate taxa	J. acutus subsp. leopoldii
Synonyms		J. glaucus
Name authority	Linnaeus: Sp. Pl. 1: 325. (1753)	Linnaeus: Sp. Pl. 1: 326. (1753)
Web links	Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR, WA Local Web sites: Flora NW, MI Flora, 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 acutus

Juncus inflexus

sharp rush, spiny rush

blue rush, European blue rush, European Meadow rush

Habit

Herbs, perennial, cespitose, stooling, 4–10 (–12) dm.

Rhizomes

3–5 mm diam.

Culms

terete, 1.5–3 mm diam.

Cataphylls

several.

Leaves

blade absent.

Inflorescences

many flowered, open, 2–7 cm;

primary bract terete, 10–25 cm.

Flowers

pedicellate;

bracteoles ovate;

tepals straw-colored to reddish brown, lanceolate, 2.7–3.5 mm, margins scarious;

inner series loosely subtending capsule at maturity, shorter;

stamens 6, filaments 0.8–1.5 mm, anthers 0.8–1 mm;

style 0.3 mm.

Capsules

reddish brown to chestnut brown, 3-locular, 3-gonous-ovoid to widely ellipsoid, 3–4 mm, exceeding perianth.

Seeds

amber, obovoid, 0.3–0.5 mm, not tailed.

= 20, 38, 40.

Juncus acutus

Juncus inflexus

Phenology

Flowering and fruiting summer.

Habitat

Wet soils along streams, ditches, and on wet, sandy and peaty hillsides

Distribution

AZ; CA; NV; South America; Mexico (Baja Calif); South Africa; Atlantic Islands

[WildflowerSearch map]

[BONAP county map]

MI; NY; PA; VA; ON; Europe; Asia; Africa [Introduced in North America]

[BONAP county map]

Discussion

Subspecies 2 (1 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source

FNA vol. 22, p. 237.

FNA vol. 22.

Parent taxa

Juncaceae > Juncus > subg. Juncus

Juncaceae > Juncus > subg. Genuini

Sibling taxa

J. acuminatus, J. acutiflorus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. cooperi, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. inflexus, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. polycephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides

J. acuminatus, J. acutiflorus, J. acutus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. cooperi, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. polycephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides

Subordinate taxa

J. acutus subsp. leopoldii

Synonyms

J. glaucus

Name authority

Linnaeus: Sp. Pl. 1: 325. (1753)

Linnaeus: Sp. Pl. 1: 326. (1753)

Web links

Local floras: OR, WA
Local Web sites: Flora NW, MI Flora, 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 the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

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

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Flora of North America species comparison

Juncus acutus

Juncus inflexus

Juncus acutus

Juncus inflexus