Hypericum mutilum |
Hypericum canadense |
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dwarf St. John's-wort, small Canadian St. John's-wort, small flower st john's wort |
Canadian St. John's-wort, lesser Canadian St. John's wort, lesser St. John's-wort, millepertuis de Canada |
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Habit | Herbs annual or perennial, usually erect, sometimes decumbent and rooting, basal branches sometimes present, usually with to 10 pairs of spreading branches distal to middle, 0.5–8 dm. | Herbs annual or perennial, erect, basal branches relatively few or none, usually with strict, ascending branches from distal nodes, 0.3–7.5 dm. | ||||
Stems | internodes 4-angled. |
internodes 4-angled. |
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Leaves | spreading, sessile or amplexicaul; blade paler abaxially, ovate, elliptic, or elliptic-oblong (proximal), ovate or suborbiculate to elliptic or lanceolate (mid and distal), 3–27(–40) × 1–15 mm, papery to membranous, margins plane, apex obtuse to rounded, basal veins 3–5, midrib with to 3 pairs of branches. |
erect or spreading, sessile or subsessile; blade linear to oblanceolate-linear or (proximal) oblanceolate to obovate, 6–55 × 0.5–5.5 mm, papery to membranous, margins plane, apex rounded, basal or near-basal veins 1–3(–5), midrib with 1–4 pairs of branches. |
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Inflorescences | cylindric, 5–60-flowered, branching mostly dichasial; bracts linear-subulate. |
corymbiform to cylindric, usually diffuse, 1–35-flowered, branching mostly dichasial. |
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Flowers | 3–5 mm diam.; sepals lanceolate to linear-lanceolate or elliptic-oblong to oblanceolate, equal or unequal, 2–4.5 × 0.6–1.5 mm, margins sometimes ciliate, not setulose-ciliate, apex usually acute to apiculate, sometimes obtuse to rounded; petals pale yellow, oblong, 1.7–3.5 mm; stamens 5–16, scarcely grouped; styles 0.5 mm; stigmas broadly capitate. |
5–6 mm diam.; sepals linear-lanceolate to lanceolate, equal, 2.5–4.5 × 0.8–1 mm, margins sometimes ciliate, not setulose-ciliate, apex acute to acuminate; petals golden yellow, sometimes red-veined, narrowly obovate to elliptic, 2.5–4 mm; stamens 12–25, obscurely 3–5-fascicled; styles 0.5–0.8 mm; stigmas broadly capitate. |
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Capsules | narrowly ovoid to cylindric-ellipsoid, 2–5 × 1.6–2.4 mm, usually broadest at or near middle. |
narrowly conic to conic-cylindric, 4–6 × 1.5–3 mm, broadest proximal to middle. |
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Seeds | 0.4–0.7 mm; testa finely linear-scalariform. |
0.5–0.7 mm; testa finely linear-scalariform. |
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2n | = 16. |
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Hypericum mutilum |
Hypericum canadense |
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Phenology | Flowering summer (Jun–Sep). | |||||
Habitat | Fens, marshes, depressions, lake and pond margins | |||||
Elevation | 0–500 m (0–1600 ft) | |||||
Distribution |
AL; AR; CA; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MS; NC; NE; NH; NJ; NY; OH; OK; OR; PA; RI; SC; TN; TX; UT; VA; VT; WA; WI; WV; BC; NB; NS; ON; QC; SK [Introduced in w North America]
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CT; DC; DE; FL; GA; IA; IL; IN; KY; MA; MD; ME; MI; MN; MS; NC; NH; NJ; NY; OH; OR; PA; RI; SC; TN; VA; VT; WA; WI; WV; NB; NF; NS; ON; PE; QC; SPM [Introduced in Europe (Ireland, The Netherlands)]
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Discussion | Subspecies 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Hypericum canadense is closely related to H. majus; it hybridizes with that species and with H. mutilum, producing intermediate forms. Hypericum ×dissimulatum E. P. Bicknell appears to comprise a continuous series of hybrids between H. canadense and H. mutilum or H. boreale such that it is not always possible to say which of these species is involved. Hypericum ×dissimulatum has been recorded from New Brunswick, Newfoundland, Nova Scotia, Ontario, and Quebec and from Connecticut, Maine, Maryland, Massachusetts, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, and Virginia. J. Rousseau reduced Hypericum canadense var. minimum to a form; it does not seem to merit any recognition. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 6, p. 93. | FNA vol. 6, p. 92. | ||||
Parent taxa | Hypericaceae > Hypericum > sect. Brathys | Hypericaceae > Hypericum > sect. Brathys | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Sarothra mutila | Brathys canadensis, H. canadense var. galiiforme, H. canadense var. magninsulare, H. canadense var. minimum | ||||
Name authority | Linnaeus: Sp. Pl. 2: 787. (1753) | Linnaeus: Sp. Pl. 2: 785. (1753) | ||||
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