Juncus brachycephalus |
Juncus canadensis |
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small-head rush |
Canada rush, Canadian rush |
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Habit | Herbs, perennial, cespitose, 2–7 dm. | Herbs, perennial, cespitose, 3–10 dm. |
Culms | erect, 1–4 mm diam., smooth. |
erect, 1–5 mm diam., smooth. |
Cataphylls | 1–2, straw-colored to pink, apex acute. |
0 or 1–2, straw-colored, apex rounded. |
Leaves | basal 1–3, cauline 1–2; auricles 0.6–1.5 mm, apex rounded, scarious; blade terete to compressed, 0.2–12 cm × 0.5–2 mm. |
basal 1, cauline 2–3; auricles 1–1.2 mm, apex rounded, scarious; blade terete, 7–22 cm × 1.2–3 mm. |
Inflorescences | panicles of 5–80 heads, 5–25 cm, branches ascending; primary bract erect; heads 2–6-flowered, ellipsoid to obovoid, 2–5 mm diam. |
panicles or racemes of 3–50 heads, 2–20 cm, branches erect to ascending; primary bract erect; heads 5–50-flowered, obconic to spheric, 3–10 mm diam. |
Flowers | tepals green to light brown, lanceolate; outer tepals 1.8–2.5 mm, apex obtuse to nearly acute; inner tepals 2–2.8 mm, apex obtuse to nearly acute; stamens 3 or 6, anthers 1/2 filament length. |
tepals green or straw-colored to reddish brown, lanceolate; outer tepals 2.7–3.8 mm, apex acuminate; inner tepals 2.9–4 mm, apex acuminate; stamens 3(–6), anthers 1/2 filament length. |
Capsules | exserted, chestnut to dark brown, imperfectly 3-locular, obconic, 2.4–3.8 mm, apex acute proximal to beak, valves separating at dehiscence. |
equaling perianth or exserted, chestnut brown, imperfectly 3-locular, lanceoloid, 3.3–4.5 mm, acute proximal to beak, valves separating at dehiscence. |
Seeds | ellipsoid to fusiform, 0.8–1.2 mm, tailed; body covered with whitish translucent veil. |
fusiform, 1.1–1.9 mm, tailed; body covered with whitish translucent veil. |
2n | = 80. |
= 80. |
Juncus brachycephalus |
Juncus canadensis |
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Phenology | Fruiting summer–early fall. | Fruiting mid summer–fall. |
Habitat | Calcareous marshes, wet meadows, and wetland shores | Salt, brackish, and calcareous marshes, acid bogs, roadsides, tidal flats, swamps, patterned fen, lake shores, beaches |
Elevation | 100–200 m (300–700 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; CO; CT; GA; IL; IN; MA; ME; MI; MN; NC; ND; NH; NJ; NY; OH; OK; PA; TN; VA; VT; WI; WV; NB; NS; ON; QC;
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AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OR; PA; RI; SC; SD; TN; VA; VT; WI; WV; MB; NB; NF; NS; ON; PE; QC; SPM
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Discussion | Two varieties and two forms occurring within the flora have been recognized (M. L. Fernald 1945b). Juncus canadensis var. sparsiflorus has stiffly erect inflorescence branches, and the flowers are generally longer than those of var. canadensis. These varieties simply serve to give name to parts of the broad morphologic range of variation encountered in J. canadensis and do not appear to represent any distinct biological entities. Juncus canadensis and the following three species form a distinctive group: they have ve been variously treated as speecies (as here), varieties of J. canadensis, or as two species, J. canadensis and a polymorphic species, J. brachysephalus, encompassing the other three species (B. Boivin 1967–1979, part IV). Most of the species are easily recognized at their extremes but show a fair amount of overlap. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Juncaceae > Juncus > subg. Septati | Juncaceae > Juncus > subg. Septati |
Sibling taxa | ||
Synonyms | J. canadensis var. brachycephalus | J. canadensis var. longicaudatus, J. canadensis var. sparsiflorus, J. longicaudatus, J. polycephalus var. paradoxus |
Name authority | (Engelmann) Buchenau: Botanische Jahrbucher fur Systematik, Pflanzengeschichte und Pflanzengeographie 12: 268. (1890) | J. Gay ex Laharpe: in J. J. C. de Laharpe, Essai Monogr. Jonc. 46. (1825) |
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