FNA: Juncus effusus vs. Juncus caesariensis

	Juncus effusus	Juncus caesariensis
	common bog rush, common rush, common soft rush, pasture rush, soft or lamp rush, soft rush	New Jersey rush
Habit	Herbs, perennial, 4–13 dm.	Herbs, perennial, cespitose, 3–9 dm.
Rhizomes	short -branched, forming distinct, often large clumps.
Culms	erect, terete, 1–2.5 mm diam. at top of sheaths.	erect, 2–4 mm diam., scabrous.
Cataphylls	several.	0 or 1–2, straw-colored, apex acuminate.
Leaves	blade absent.	basal 1–2, cauline 1–2; auricles 1–7.5 mm, apex rounded, scarious; blade terete, 4–25 cm × 1–1.8 mm, scabrous.
Inflorescences	lateral, compound dichasia, many flowered; primary bract erect, terete, extending well beyond dichasium.	panicles of 5–30 heads, 12–15 cm, erect to ascending branches; primary bract erect; heads 2–6-flowered, broadly obovoid, 5–10 mm diam.
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.	tepals green to reddish brown, lanceolate; outer tepals 3.3–3.9 mm, apex acuminate; inner tepals 3.9–4.7 mm, acuminate; stamens 6, anthers 1/2 filament length.
Capsules	greenish tan or darker, 3-locular, broadly ellipsoid to oblate, 1.5–3.2 mm.	exserted, chestnut brown, 3-locular, ovoid, 4.5–5.3 mm, apex acuminate, valves separating at dehiscence.
Seeds	amber, (0.3–)0.4–0.5 mm.	fusiform, 2.2–2.6 mm, tailed.
; seed body covered with whitish translucent veil.
2n	= 40, 42.

	Juncus effusus	Juncus caesariensis
Phenology	Flowering summer, fruiting summer–fall.	Fruiting mid summer–early fall.
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	Wet springy bogs, swamps, and borders of wet woods
Elevation	Habitat??; 0–2500 m [Habitat??; 0–8200 ft]	0–100 m [0–300 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]	DC; DE; MD; NC; NJ; PA; VA; NS [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. Septati
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. 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
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. asper
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	Local Web sites: MD Biodiversity WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Juncus caesariensis

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

New Jersey rush

Habit

Herbs, perennial, 4–13 dm.

Herbs, perennial, cespitose, 3–9 dm.

Rhizomes

short -branched, forming distinct, often large clumps.

Culms

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

erect, 2–4 mm diam., scabrous.

Cataphylls

several.

0 or 1–2, straw-colored, apex acuminate.

Leaves

blade absent.

basal 1–2, cauline 1–2;

auricles 1–7.5 mm, apex rounded, scarious;

blade terete, 4–25 cm × 1–1.8 mm, scabrous.

Inflorescences

lateral, compound dichasia, many flowered;

primary bract erect, terete, extending well beyond dichasium.

panicles of 5–30 heads, 12–15 cm, erect to ascending branches;

primary bract erect;

heads 2–6-flowered, broadly obovoid, 5–10 mm diam.

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.

tepals green to reddish brown, lanceolate;

outer tepals 3.3–3.9 mm, apex acuminate;

inner tepals 3.9–4.7 mm, acuminate;

stamens 6, anthers 1/2 filament length.

Capsules

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

exserted, chestnut brown, 3-locular, ovoid, 4.5–5.3 mm, apex acuminate, valves separating at dehiscence.

Seeds

amber, (0.3–)0.4–0.5 mm.

fusiform, 2.2–2.6 mm, tailed.

; seed body covered with whitish translucent veil.

= 40, 42.

Juncus caesariensis

Phenology

Flowering summer, fruiting summer–fall.

Fruiting mid summer–early fall.

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

Wet springy bogs, swamps, and borders of wet woods

Elevation

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

0–100 m [0–300 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]

DC; DE; MD; NC; NJ; PA; VA; NS

[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. Septati

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. 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

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. asper

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 caesariensis

Juncus effusus

Juncus caesariensis