Triadenum virginicum

(Linnaeus) Rafinesque

Fl. Tellur. 3: 79. 1837.

Common names: Millepertuis de Virginie
Basionym: Hypericum virginicum Linnaeus Syst. Nat. ed. 10, 2: 1184. 1759
Synonyms: Elodes campanulata (Walter) Pursh E. campanulata var. emarginata (Lamarck) Pursh E. virginica (Linnaeus) Farwell Gardenia virginica Walter Hypericum campanulatum Stokes H. enneandrum (Walter) Sprengel Martia campanulata
Treatment appears in FNA Volume 6. Treatment on page 103.

Herbs erect, 2–7 dm, sometimes with ascending branches distally. Stems: internodes 4-lined or 4-angled at first, then terete. Leaves 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 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 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 to ellipsoid or ovoid-ellipsoid, (8–)9–10(–12) × 4–5 mm, apex acute. Seeds 0.5–1.2 mm. 2n = 38.

Phenology: Flowering summer–fall (Jul–Oct).
Habitat: Swamps, marshy shores, poor fens
Elevation: 0–500 m


V6 182-distribution-map.jpg

N.S., Ont., Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Ky., La., Maine, Md., Mass., Mich., Miss., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.


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).

Selected References


Lower Taxa

... more about "Triadenum virginicum"
Norman K. B. Robson +
(Linnaeus) Rafinesque +
Hypericum virginicum +
Millepertuis de Virginie +
N.S. +, Ont. +, Ala. +, Ark. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Miss. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +  and Wis. +
0–500 m +
Swamps, marshy shores, poor fens +
Flowering summer–fall (Jul–Oct). +
Fl. Tellur. +
Endemic +  and Illustrated +
Elodes campanulata +, E. campanulata var. emarginata +, E. virginica +, Gardenia virginica +, Hypericum campanulatum +, H. enneandrum +  and Martia campanulata +
Triadenum virginicum +
Triadenum +
species +