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greater Canada St. John's-wort, greater Canadian St. John's-wort, large Canadian St. John's-wort, large St. John's wort, millepertuis majeur
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Herbs, annual or perennial (stems and leaves glabrous except 43. H. setosum); black glands absent. |
Herbs perennial, erect, branching at base and in inflorescence, branches relatively few, 0.5–7 dm. |
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internodes 4-angled. |
deciduous (base articulated) or persistent (base not articulated). |
spreading, sessile or distal subamplexicaul; blade lanceolate to narrowly oblong-elliptic or (proximal) oblanceolate, 10–45 × (2–)6–12 mm, papery to membranous, margins plane, apex acute to rounded, basal or near-basal veins (3–)5–7, midrib with to 4 pairs of branches. |
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corymbiform to cylindric, 3–30-flowered, usually compact, branching mostly dichasial. |
3–15 mm diam.; sepals persistent, (4–)5; petals persistent, (4–)5; stamens persistent, (5–)10–80, usually in continuous or interrupted ring, sometimes in 5 barely discernable fascicles, each of 1–2 stamens; ovary (2–)3(–4)-merous; placentation parietal; styles ± spreading, bases distinct; stigmas capitate or clavate. |
6–7 mm diam.; sepals lanceolate to narrowly elliptic, equal, 3.5–6.5 × 0.8–1.5 mm, margins sometimes ciliate, not setulose-ciliate, apex acute; petals golden yellow, sometimes red-veined, oblanceolate, 3.5–6 mm; stamens 12–21, obscurely 5-fascicled; styles 0.6–1 mm; stigmas broadly capitate. |
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narrowly conic-ellipsoid, 4–8 × 2.5–3.5 mm, broadest proximal to middle. |
not carinate. |
0.5–0.7 mm; testa finely linear-scalariform. |
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= 16. |
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Flowering summer (Jun–Sep). |
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Fens, marshes, ditches, lake and stream margins, other damp habitats |
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0–1200 m [0–3900 ft] |
North America; Mexico; Central America; South America; West Indies; Africa; Asia; Pacific Islands (New Zealand); Australia |
CO; CT; IA; ID; IL; IN; KS; MA; ME; MI; MN; MO; MT; ND; NE; NH; NJ; NY; OH; OR; PA; RI; SD; VT; WA; WI; AB; BC; MB; NB; NS; ON; PE; QC; SK [Introduced in Europe (France, Germany), e Asia (Japan)]
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Species 148 (16 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Hypericum majus was the western member of a vicariant species pair, differing from the originally eastern member (H. canadense) by the broader leaves, usually more-congested inflorescence, and larger flowers. These species became sympatric in glaciated northeastern North America and now hybridize freely, notably in Wisconsin (F. H. Utech and H. H. Iltis 1970). Hybrids are intermediate in form between the parents and have also been recorded from Connecticut, Massachusetts, and New Hampshire. Hypericum majus hybridizes also with H. mutilum, with subsp. mutilum in Maine, and with subsp. boreale in Michigan and Wisconsin. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
1. Herbs annual, wiry; inflorescences: branching mostly monochasial | → 2 |
1. Herbs annual or perennial, not wiry; inflorescences: branching mostly dichasial | → 3 |
2. Leaf blades linear or linear-subulate to linear-lanceolate, 5–22 mm, margins recurved to revolute; sepals 3–7 mm; capsule lengths 1–1.2 times sepals. | H. drummondii |
2. Leaf blades narrowly triangular-subulate to linear-subulate, scalelike, 1–4 mm, margins incurved; sepals 1.5–2.5 mm; capsule lengths 2–2.7 times sepals. | H. gentianoides |
3. Stems and leaves scabrous-tomentose to pilose; sepal margins setulose-ciliate. | H. setosum |
3. Stems and leaves glabrous; sepal margins sometimes ciliate, not setulose-ciliate | → 4 |
4. Leaf blades linear-subulate, 0.2–0.3 mm wide, basal veins 1, midrib unbranched. | H. cumulicola |
4. Leaf blades not linear-subulate, (0.5–)2–18 mm wide, basal veins 1–7, midrib with 0–4 pairs of branches | → 5 |
5. Leaf blades leathery; petals golden yellow or orange-yellow; stamens (35–) 50–80 | → 6 |
5. Leaf blades papery to membranous; petals usually bright, golden, or pale yellow, rarely salmon-orange; stamens 5–25 | → 11 |
6. Leaf blades linear-oblong or linear-lanceolate to linear, 0.5–2 mm wide; petals red tinged; stamens 35–50; styles 2.5–5 mm | H. paucifolium |
6. Leaf blades elliptic, lanceolate, linear-lanceolate, oblong-elliptic, obovate, or ovate, 3–18 mm wide; petals not red tinged; stamens 50–80; styles 2–4 mm | → 7 |
7. Herbs erect or ± spreading, non-aerenchymatous at base; leaves (main stems) longer than internodes | → 8 |
7. Herbs erect to ascending, usually ± aerenchymatous (spongiform-thickened) at base; leaves (main stems) mostly shorter than internodes (usually longer in. 31 H. harperi). | → 9 |
8. Leaf blades (main stem) lanceolate to oblong-elliptic or obovate, 10–30(–50) mm, apex usually acute to acuminate, rarely obtuse; subsidiary inflorescence branches with or without relatively smaller leaves. | H. virgatum |
8. Leaf blades (main stem) narrowly lanceolate, 10–40(–55) mm, apex acute to acuminate; subsidiary inflorescence branches with relatively smaller leaves. | H. radfordiorum |
9. Herbs 2–7 dm; leaf blades (main stem) usually broadly to narrowly ovate, rarely elliptic or lanceolate. | H. denticulatum |
9. Herbs 3–12 dm; leaf blades (main stem) usually lanceolate, sometimes linear-lanceolate or oblong-elliptic, rarely elliptic or ovate | → 10 |
10. Herbs erect to ascending, branching at base and in inflorescence; leaves strongly ascending to appressed, shorter than internodes, smaller distally. | H. erythreae |
10. Herbs erect, branching (from long-creeping rhizomes) at base and from mid and distal nodes; leaves ascending to deflexed, mostly longer than internodes, not or scarcely smaller distally. | H. harperi |
11. Herbs decumbent to ascending, forming loose mats; stigmas scarcely capitate. | H. anagalloides |
11. Herbs usually erect, not forming loose mats; stigmas broadly capitate | → 12 |
12. Leaf blades lanceolate, linear, narrowly elliptic, narrowly oblong-elliptic, oblanceolate, oblanceolate-linear, or obovate; capsules broadest proximal to middle | → 13 |
12. Leaf blades usually elliptic, oblong, broadly oblong-elliptic, ovate, ovate-triangular, round, or suborbiculate, rarely lanceolate; capsules usually broadest at or near middle | → 14 |
13. Leaf blades lanceolate, narrowly oblong-elliptic, or oblanceolate, (2–)6–12 mm wide, basal veins (3–)5–7; inflorescences usually compact. | H. majus |
13. Leaf blades linear to oblanceolate-linear or (proximal) oblanceolate to obovate, 0.5–5.5 mm wide, basal veins 1–3(–5); inflorescences usually diffuse. | H. canadense |
14. Leaf blades (mid and distal) lanceolate-deltate, apex usually subacute; capsules narrowly conic-ellipsoid. | H. gymnanthum |
14. Leaf blades (mid and distal) elliptic, lanceolate, oblanceolate, oblong, round, suborbiculate, or ovate, apex obtuse to rounded; capsules narrowly ovoid to cylindric-ellipsoid | → 15 |
15. Leaf blades bicolor, paler abaxially; inflorescences: bracts linear-subulate. | H. mutilum |
15. Leaf blades concolor; inflorescences: bracts not linear-subulate. | H. boreale |
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FNA vol. 6, p. 88. |
FNA vol. 6, p. 91. Treatment author: Norman K. B. Robson. |
Hypericaceae > Hypericum |
Hypericaceae > Hypericum > sect. Brathys |
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H. adpressum, H. anagalloides, H. apocynifolium, H. ascyron, H. boreale, H. brachyphyllum, H. buckleyi, H. canadense, H. canariense, H. chapmanii, H. cistifolium, H. concinnum, H. crux-andreae, H. cumulicola, H. densiflorum, H. denticulatum, H. dolabriforme, H. drummondii, H. edisonianum, H. ellipticum, H. erythreae, H. fasciculatum, H. frondosum, H. galioides, H. gentianoides, H. graveolens, H. gymnanthum, H. harperi, H. hypericoides, H. kalmianum, H. lissophloeus, H. lloydii, H. lobocarpum, H. maculatum, H. microsepalum, H. mutilum, H. myrtifolium, H. nitidum, H. nudiflorum, H. paucifolium, H. perforatum, H. prolificum, H. pseudomaculatum, H. punctatum, H. radfordiorum, H. scouleri, H. setosum, H. sphaerocarpum, H. suffruticosum, H. tenuifolium, H. tetrapetalum, H. virgatum, H. ×mitchellianum |
H. anagalloides, H. boreale, H. canadense, H. cumulicola, H. denticulatum, H. drummondii, H. erythreae, H. gentianoides, H. gymnanthum, H. harperi, H. majus, H. mutilum, H. paucifolium, H. radfordiorum, H. setosum, H. virgatum |
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section Brathys, H. section Brathys, H. section Spachium, H. subsection Spachium, H. section Trigynobrathys, Sarothra section Trigynobrathys |
H. canadense var. majus, H. mutilum var. longifolium, Sarothra major |
unknown |
(A. Gray) Britton: Mem. Torrey Bot. Club 5: 225. (1894) |
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