FNA: Juncus effusus vs. Juncus gymnocarpus

	Juncus effusus	Juncus gymnocarpus
	common bog rush, common rush, common soft rush, pasture rush, soft or lamp rush, soft rush	Pennsylvania rush
Habit	Herbs, perennial, 4–13 dm.	Herbs, perennial, 5–10 dm.
Rhizomes	short -branched, forming distinct, often large clumps.	widely creeping, 2–4 mm diam.
Culms	erect, terete, 1–2.5 mm diam. at top of sheaths.	terete, 1.5–2.5 mm diam.
Cataphylls	several.	several.
Leaves	blade absent.	blade absent.
Inflorescences	lateral, compound dichasia, many flowered; primary bract erect, terete, extending well beyond dichasium.	8–30(–50)-flowered, open, 1.5–4 cm; primary bract terete, 1–2.5 dm, much longer than inflorescence.
Flowers	tepals tan or darker, usually with greenish midstripe, lanceolate, 1.9–3.5 mm; inner slightly shorter; stamens 3, filaments 0.5–0.8 mm, anthers 0.5–0.8 mm; style 0.2 mm.	pedicellate; bracteoles broadly ovate; tepals light brown, ovate-lanceolate, 1.8–2.5 mm, apex acuminate; inner series shorter, margins scarious, apex acute; stamens 6, filaments 1–1.3 mm, anthers 0.5–0.7 mm; style 0.5 mm.
Capsules	greenish tan or darker, 3-locular, broadly ellipsoid to oblate, 1.5–3.2 mm.	reddish tan to brown, lustrous, 3-locular, widely ellipsoid, 2–3 × 1.8–2.2 mm, exceeding perianth.
Seeds	amber, (0.3–)0.4–0.5 mm.	dark amber, obovoid, 0.7–1 mm, not tailed.
2n	= 40, 42.

	Juncus effusus	Juncus gymnocarpus
Phenology	Flowering summer, fruiting summer–fall.	Flowering and fruiting summer.
Habitat	Swamps and their edges, marshes, moist meadows, and moist or saturated soils, often conspicuous in pasture meadows where it is shunned by grazing animals	Sphagnous swamps, low woods, edges of lakes
Elevation	Habitat??; 0–2500 m [Habitat??; 0–8200 ft]	600–1500 m [2000–4900 ft]
Distribution	AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NV; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; WV; BC; MB; NB; NF; NS; ON; PE; QC [WildflowerSearch map] [BONAP county map]	AL; FL; MS; NC; PA; SC; TN [WildflowerSearch map] [BONAP county map]
Discussion	The Juncus effusus complex has been variously recognized as containing several species or a single species with numerous infraspecific taxa. Unfortunately, North American treatments have dealt primarily with taxa in either the eastern or western portions of the continent. In considering the continent as a whole, little sense can be made of these treatments. The North American J. effusus complex is one that is in obvious need of modern systematic scrutiny. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Parent taxa	Juncaceae > Juncus > subg. Genuini	Juncaceae > Juncus > subg. Genuini
Sibling taxa	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. 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. 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
Synonyms	J. conglomeratus, J. effusus var. brunneus, J. effusus var. caeruleomontanus, J. effusus var. costulatus, J. effusus var. dicipiens, J. effusus var. exiguus, J. effusus var. gracilis, J. effusus var. pylaei, J. effusus var. solutus, J. effusus var. subglomeratus, J. griscomii	J. smithii
Name authority	Linnaeus: Sp. Pl. 1: 326. (1753)	Coville: Memoirs of the Torrey Botanical Club 5: 106. (1894)
Source	FNA vol. 22. Treatment authors: Ralph E. Brooks, Steven E. Clemants.	FNA vol. 22. Treatment authors: Ralph E. Brooks, Steven E. Clemants.
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, Go Botany, IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, MI Flora, MN Wildflowers, MO Plants, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Juncus gymnocarpus

common bog rush, common rush, common soft rush, pasture rush, soft or lamp rush, soft rush

Pennsylvania rush

Habit

Herbs, perennial, 4–13 dm.

Herbs, perennial, 5–10 dm.

Rhizomes

short -branched, forming distinct, often large clumps.

widely creeping, 2–4 mm diam.

Culms

erect, terete, 1–2.5 mm diam. at top of sheaths.

terete, 1.5–2.5 mm diam.

Cataphylls

several.

Leaves

blade absent.

Inflorescences

lateral, compound dichasia, many flowered;

primary bract erect, terete, extending well beyond dichasium.

8–30(–50)-flowered, open, 1.5–4 cm;

primary bract terete, 1–2.5 dm, much longer than inflorescence.

Flowers

tepals tan or darker, usually with greenish midstripe, lanceolate, 1.9–3.5 mm;

inner slightly shorter;

stamens 3, filaments 0.5–0.8 mm, anthers 0.5–0.8 mm;

style 0.2 mm.

pedicellate;

bracteoles broadly ovate;

tepals light brown, ovate-lanceolate, 1.8–2.5 mm, apex acuminate;

inner series shorter, margins scarious, apex acute;

stamens 6, filaments 1–1.3 mm, anthers 0.5–0.7 mm;

style 0.5 mm.

Capsules

greenish tan or darker, 3-locular, broadly ellipsoid to oblate, 1.5–3.2 mm.

reddish tan to brown, lustrous, 3-locular, widely ellipsoid, 2–3 × 1.8–2.2 mm, exceeding perianth.

Seeds

amber, (0.3–)0.4–0.5 mm.

dark amber, obovoid, 0.7–1 mm, not tailed.

= 40, 42.

Juncus gymnocarpus

Phenology

Flowering summer, fruiting summer–fall.

Flowering and fruiting summer.

Habitat

Swamps and their edges, marshes, moist meadows, and moist or saturated soils, often conspicuous in pasture meadows where it is shunned by grazing animals

Sphagnous swamps, low woods, edges of lakes

Elevation

Habitat??; 0–2500 m [Habitat??; 0–8200 ft]

600–1500 m [2000–4900 ft]

Distribution

AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NV; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; WV; BC; MB; NB; NF; NS; ON; PE; QC

[WildflowerSearch map]

[BONAP county map]

AL; FL; MS; NC; PA; SC; TN

[WildflowerSearch map]

[BONAP county map]

Discussion

The Juncus effusus complex has been variously recognized as containing several species or a single species with numerous infraspecific taxa. Unfortunately, North American treatments have dealt primarily with taxa in either the eastern or western portions of the continent. In considering the continent as a whole, little sense can be made of these treatments. The North American J. effusus complex is one that is in obvious need of modern systematic scrutiny.

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

Parent taxa

Juncaceae > Juncus > subg. Genuini

Sibling taxa

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. 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. 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

Synonyms

J. conglomeratus, J. effusus var. brunneus, J. effusus var. caeruleomontanus, J. effusus var. costulatus, J. effusus var. dicipiens, J. effusus var. exiguus, J. effusus var. gracilis, J. effusus var. pylaei, J. effusus var. solutus, J. effusus var. subglomeratus, J. griscomii

J. smithii

Name authority

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

Coville: Memoirs of the Torrey Botanical Club 5: 106. (1894)

Source

FNA vol. 22. Treatment authors: Ralph E. Brooks*, Steven E. Clemants*.

Web links

Local floras: BC, CA, OR, WA
Local Web sites: CalFlora, CalPhotos, Flora NW, Go Botany, IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, MI Flora, MN Wildflowers, MO Plants, 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).

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Juncus effusus

Juncus gymnocarpus

Juncus effusus

Juncus gymnocarpus