Juncus bufonius |
Juncus articulatus |
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common toad rush, toad rush |
joint-leaf rush, jointed rush |
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Habit | Herbs, annual, cespitose, 0.5–4 dm. | Herbs, perennial, rhizomatous to nearly cespitose, 0.5–6(–10) dm. |
Rhizomes | 2–3 mm diam., not swollen. |
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Culms | 1–many, occasionally becoming decumbent. |
erect to decumbent (and floating), terete, 1–3 mm diam., smooth. |
Cataphylls | 0–2. |
1, maroon to straw-colored, apex acute to obtuse. |
Leaves | basal and cauline; auricles rudimentary or absent; blade flat, 3–13 cm × 0.3–1.1 mm. |
basal 0–2, cauline (1–)3–6; auricles 0.5–1 mm, apex rounded, scarious; blade green to straw-colored, terete, 3.5–12 cm × 0.5–1.1 mm. |
Inflorescences | loose and diffuse or less often compact, usually at least ½1/2 total height of plant; primary bract shorter than inflorescence. |
terminal panicles of 3–30(–50) heads, 3.5–8 cm, branches spreading; primary bract erect; heads 3–10-flowered, obpyramidal to hemispheric, 6–8 mm diam. |
Flowers | bracteoles 2; tepals greenish, lanceolate, 3.8–7(–8.5) mm; inner series slightly shorter, apex sometimes obtuse; stamens 3–6, filaments (0.7–)1–1.8 mm, anthers 0.3–0.8 mm; style 0.1–0.2 mm. |
tepals green to straw-colored or dark brown, ovate to lanceolate, 1.8–3 mm; outer tepals with apex acute or acuminate; inner tepals with apex acute acuminate to obtuse; stamens 6, anthers equal to filament length. |
Capsules | tan to reddish brown, 3-locular, ellipsoid to narrowly so, slightly truncate, 2.7–4 × 1–1.5 mm, sometimes exceeding inner tepals but usually not outer series. |
exserted ca. 1 mm beyond perianth, chestnut brown to dark brown, imperfectly 3-locular, ellipsoid or ovoid, 2.8–4 mm, apex acute proximal to beak, valves separating at dehiscence. |
Seeds | yellowish, widely ellipsoid to ovoid, 0.26–0.49, not tailed. |
obovoid, 0.5 mm, not tailed. |
2n | = 27–37, 58–81, 108–115. |
= 80. |
Juncus bufonius |
Juncus articulatus |
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Phenology | Flowering and fruiting spring–early fall. | Fruiting mid summer–fall. |
Habitat | Moist soils in meadows, along lakeshores or stream banks, ditches, or roadsides, especially frequent in drawdown areas, usually in open sites and often becoming weedy | Wet ground in ditches, lake and stream margins, and a variety of other habitats, often a calciphile |
Elevation | 0–3000 m (0–9800 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; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NL; NS; NT; ON; PE; QC; SK; YT; Greenland; nearly worldwide
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AK; AZ; CA; CO; CT; ID; IN; KY; MA; ME; MI; MN; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SD; UT; VA; VT; WA; WV; BC; NB; NF; NS; ON; PE; QC; SPM; Eurasia
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Discussion | Nearly worldwide, Juncus bufonius is found essentially throughout North America except north of the Alaskan and Canadian tTaiga. Juncus bufonius is a highly polymorphic complex that is poorly understood systematically. Insufficient evidence exists upon which to base the segregation of the plethora of taxa that have been recognized out of this group in the past. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Juncus articulatus hybridizes with J. brevicaudatus (= J. ×fulvescens Fernald), J. alpinus (= J. ×alpiniformis Fernald), J. nodosus, and J. canadensis. Juncus articulatus var. obtusatus Engelmann appears to be intermediate with J. alpinus. It has spreading inflorescence branches but obtuse inner tepals. This may represent a backcross with J. alpinus. Recent evidence suggests that J. alpinus is a polyploid species with J. articulatus as one of its parents. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Poiophylli | Juncaceae > Juncus > subg. Septati |
Sibling taxa | ||
Synonyms | J. bufonius var. congestus, J. bufonius var. halophilus, J. bufonius var. hybridus, J. bufonius var. occidentalis, J. bufonius var. ranarius, J. congestus, J. ranarius | J. articulatus var. obtusatus, J. articulatus var. stolonifer, J. lampocarpus |
Name authority | Linnaeus: Sp. Pl. 1: 328. (1753) | Linnaeus: Sp. Pl. 1: 327. (1753) |
Web links |
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