Hypericum mutilum

Linnaeus
Sp. Pl. 2: 787. 1753.
Common names: Dwarf St. John’s wort
WeedyEndemic
Synonyms: Sarothra mutila (Linnaeus) Y. Kimura
Treatment appears in FNA Volume 6. Treatment on page 93. Mentioned on page 86, 89, 92, 94.

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. Stems: internodes 4-angled. 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. Inflorescences cylindric, 5–60-flowered, branching mostly dichasial; bracts linear-subulate. 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. Capsules narrowly ovoid to cylindric-ellipsoid, 2–5 × 1.6–2.4 mm, usually broadest at or near middle. Seeds 0.4–0.7 mm; testa finely linear-scalariform.

Distribution

V6 158-distribution-map.jpg

B.C., N.B., N.S., Ont., Que., Sask., Ala., Ark., Calif., Colo., Conn., D.C., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Md., Mich., Miss., Mo., N.C., N.H., N.J., N.Y., Nebr., Ohio, Okla., Oreg., Pa., R.I., S.C., Tenn., Tex., Utah, Va., Vt., W.Va., Wash., Wis., introduced in w North America.

Discussion

Subspecies 2 (2 in the flora).

Selected References

None.

Key

1 Stems: apical internode shorter than adjacent one or almost absent; inflorescences: branching mostly dichasial from 2–10 nodes. Hypericum mutilum subsp. mutilum
1 Stems: apical internode usually longer than adjacent one; inflorescences: branching from 1–4(–6) nodes, branches diffuse and repeatedly monochasial distally. Hypericum mutilum subsp. latisepalum
... more about "Hypericum mutilum"
Norman K. B. Robson +
Linnaeus +
Dwarf St. John’s wort +
B.C. +, N.B. +, N.S. +, Ont. +, Que. +, Sask. +, Ala. +, Ark. +, Calif. +, Colo. +, Conn. +, D.C. +, Del. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Mass. +, Md. +, Mich. +, Miss. +, Mo. +, N.C. +, N.H. +, N.J. +, N.Y. +, Nebr. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Utah +, Va. +, Vt. +, W.Va. +, Wash. +, Wis. +  and introduced in w North America. +
Weedy +  and Endemic +
Sarothra mutila +
Hypericum mutilum +
Hypericum sect. Brathys +
species +