Triadenum tubulosum |
Triadenum virginicum |
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lesser marsh St. Johnswort |
marsh St. John's wort, millepertuis de virginie, Virginia marsh-St. John's-wort |
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Habit | Herbs erect, to 10 dm, sometimes branching from near base, sometimes with ascending branches in distal 1/2+. | Herbs erect, 2–7 dm, sometimes with ascending branches distally. |
Stems | internodes 2-lined at first, then terete. |
internodes 4-lined or 4-angled at first, then terete. |
Leaves | sessile or (distal) subsessile, rarely amplexicaul; blade narrowly oblong or elliptic to oblanceolate, 50–120(–150) × 10–40(–50) mm, base rounded to truncate or subcordate, apex rounded or rounded-apiculate to retuse, gland dots intramarginal. |
sessile, sometimes amplexicaul; blade usually ovate or triangular-ovate to elliptic or oblong, rarely oblanceolate, 20–65 × 10–22(–30) mm, base shallowly cordate, apex usually rounded, rarely obtuse to retuse, gland dots laminar (relatively dense, large) and intramarginal (relatively small). |
Inflorescences | spiciform-cylindric, 3–7-flowered from terminal node, with sessile or pedunculate inflorescences and flowering branches from to 4 proximal nodes. |
laxly cylindric to pyramidal, 3–15-flowered from terminal node, sometimes with subsidiary inflorescences from to 4 proximal nodes and flowering branches from to 6 further nodes. |
Flowers | 15 mm diam.; sepals narrowly oblong, 4–7 × 1–1.5 mm, apex acute to obtuse; petals elliptic-obovate, 5–8 mm; stamen fascicles 4–7 mm; filaments 1/2+ connate; styles 0.8–1.5 mm. |
10–15 mm diam.; sepals oblong to elliptic-oblong or oblong-lanceolate, 4–7(–8) × 1–2 mm, apex acute to acuminate; petals oblong-elliptic to oblanceolate, 6–9(–10) mm; stamen fascicles 4–6.5 mm; filaments 1/5 connate; styles 2–3.5 mm. |
Capsules | cylindric, 8–12 × 3.5–4 mm, apex obtuse. |
cylindric to ellipsoid or ovoid-ellipsoid, (8–)9–10(–12) × 4–5 mm, apex acute. |
Seeds | 0.8–1.2 mm. |
0.5–1.2 mm. |
2n | = 38. |
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Triadenum tubulosum |
Triadenum virginicum |
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Phenology | Flowering late summer–early fall (Aug–Sep). | Flowering summer–fall (Jul–Oct). |
Habitat | Swampy or marshy ground in woods | Swamps, marshy shores, poor fens |
Elevation | 0–500 m (0–1600 ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; AR; FL; GA; IL; IN; KY; LA; MO; MS; NC; OH; SC; TN; TX; VA
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AL; AR; CT; DC; DE; FL; GA; IL; IN; KY; LA; MA; MD; ME; MI; MS; NC; NH; NJ; NY; OH; PA; RI; SC; TN; TX; VA; VT; WI; WV; NS; ON
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Discussion | The absence of laminar glands in leaves is a more reliable characteristic for differentiating Triadenum tubulosum from T. walteri than sessile versus petiolate leaves, which are not always quite sessile towards the inflorescence in T. tubulosum, or sepals, which can be obtuse in both. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Triadenum virginicum is the most widely distributed North American species of Triadenum. In the southwestern part of its range, the leaves are longer and narrower, approaching those of T. tubulosum and T. walteri; it is nearly always distinguishable from the northern T. fraseri by the sepals and styles (see key). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 6, p. 104. | FNA vol. 6, p. 103. |
Parent taxa | Hypericaceae > Triadenum | Hypericaceae > Triadenum |
Sibling taxa | ||
Synonyms | Hypericum tubulosum, Elodes drummondii, E. pauciflora, E. tubulosa, H. petiolatum var. tubulosum, H. walteri var. tubulosum, T. longifolium | Hypericum virginicum, Elodes campanulata, E. campanulata var. emarginata, E. virginica, Gardenia virginica, Hypericum campanulatum, H. enneandrum, Martia campanulata |
Name authority | (Walter) Gleason: Phytologia 2: 289. (1947) | (Linnaeus) Rafinesque: Fl. Tellur. 3: 79. (1837) |
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