39a. Hypericum mutilum Linnaeus subsp. mutilum
[E]
Millepertuis nain Millepertuis nain
Brathys euphorbioides (A. St. Hilaire) Spach; B. quinquenervia (Walter) Spach; Hypericum euphorbioides A. St. Hilaire; H. mutilum var. densiflorum Kuntze; H. mutilum var. foliosissimum Kuntze; H. mutilum var. minimum N. Coleman; H. mutilum var. parviflorum Fernald; H. quinquenervium Walter
Stems: apical internode shorter than adjacent one or almost absent. Leaf blades variable, rarely broadly ovate or suborbiculate. Inflorescences: branching from 2–10 nodes, mostly dichasial. Sepals not imbricate or broader beyond middle or, if imbricate, leaves not broadly ovate to suborbiculate. 2n = 16.
Flowering summer–fall (Jun–Oct). Ditches, marshes, lake margins, desiccated temporary pools; 0–400 m; B.C., N.B., N.S., Ont., Que., Sask.; Ala., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis.; widely introduced in Central America, South America, Europe, Pacific Islands (Hawaii, New Zealand).
The records of subsp. mutilum from British Columbia and Saskatchewan and from California, Colorado, Oregon, and Utah (no details seen) are almost certainly all the result of introduction, as may be some other peripheral records.