Flora of North America species comparison

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Juncus effusus

Juncus diffusissimus

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

diffuse rush, slim-fruit rush, slim-pod rush
Habit Herbs, perennial, 4–13 dm. Herbs, perennial, cespitose, 2.5–6.5 dm.
Rhizomes

short -branched, forming distinct, often large clumps.

Culms

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

erect, terete, 1–3 mm diam., smooth.
Cataphylls

several.

0–1, maroon or dark green, apex obtuse.
Leaves

blade absent.

basal 1, cauline 2–3;

auricles 1–2.1 mm, apex rounded, membranaceous;

blade maroon or dark green, terete to compressed, 3–20 cm × 1–2.4 mm.
Inflorescences

lateral, compound dichasia, many flowered;

primary bract erect, terete, extending well beyond dichasium.

terminal panicles of 30–70(–130), 5–20 cm, branches spreading;

primary bract erect;

;

heads (1–)2–10-flowered, hemispheric or narrower, 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 straw-colored, lanceolate, apex acute;

outer tepals (2–)2.6–3.2 mm;

inner tepals (1.8–)2.3–3 mm;

stamens 3, anthers 1/2–2/3 filament length.
Capsules

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

exserted, , straw-colored, 1-locular, linear-lanceoloid, 4–5.2 mm, apex acute, valves separating at dehiscence.
Seeds

amber, (0.3–)0.4–0.5 mm.

oblong-ellipsoid, 0.3–0.4 mm, not tailed;

body clear yellow-brown.
2n

= 40, 42.

Juncus effusus

Juncus diffusissimus
Phenology Flowering summer, fruiting summer–fall. 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 In soft mucky substrates, marshy shores, sloughs, occasionally in wet wooded places, often in shallow water, commonly abundantly colonizing wet, sandy- alluvial outwash in ditches and clearings
Elevation Habitat??; 0–2500 m [Habitat??; 0–8200 ft] 10–1000 m [30–3300 ft]
Distribution
map from FNA
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]
map from FNA
AL; AR; CA; CT; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; OH; OK; SC; TN; TX; VA; WA; WV [Probably introduced, South America]
[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. 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. 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. 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
Name authority Linnaeus: Sp. Pl. 1: 326. (1753) Buckley: Proceedings of the Academy of Natural Sciences of Philadelphia 14: 9. (1862)
Source FNA vol. 22. Treatment authors: Ralph E. Brooks*, Steven E. Clemants*. FNA vol. 22. Treatment authors: Ralph E. Brooks*, Steven E. Clemants*.
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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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