Hypericum sphaerocarpum |
Hypericum virgatum |
|
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round-fruit St. John's-wort, roundseed St. Johnswort |
sharpleaf St. Johnswort |
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Habit | Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm. | Herbs perennial, erect, unbranched or branching at base and in inflorescence, 4–7.5(–10) dm. |
Stems | internodes 2–4-lined. |
internodes 4-lined. |
Leaves | blades narrowly elliptic or narrowly oblong to linear, 30–70 × 3–15 mm, base not articulated, narrowly cuneate to linear, margins plane to revolute, apex subacute to rounded, midrib with 0–4 pairs of branches. |
(main stem) ascending to spreading, sessile; blade lanceolate to oblong-elliptic or obovate, 10–30(–50) × 3–8(–12) mm, on main stem, longer than internodes, leathery, margins plane, apex usually acute to acuminate, rarely obtuse, basal veins 1–3+, midrib with 2–3 pairs of inconspicuous branches. |
Inflorescences | rounded-corymbiform, 7–70-flowered, narrowly branched, sometimes with dichasia or branches from to 8 proximal nodes. |
broadly cylindric to corymbiform, 25–70-flowered, branching mostly dichasial, subsidiary branches with or without relatively smaller leaves. |
Flowers | 10–15 mm diam.; sepals persistent, not enclosing capsule, 5, broadly ovate to oblong-elliptic, ± unequal, 2.5–5 × 1.5–3 mm; petals 5, bright yellow, oblanceolate-elliptic to elliptic, 5–9 mm; stamens persistent, 45–85; ovary 3-merous, placentation parietal. |
8–13 mm diam.; sepals narrowly ovate to lanceolate, equal, 3–3.5 × 1.5–2.5 mm, margins sometimes ciliate, not setulose-ciliate, apex acute to acuminate; petals orange-yellow, obovate, 6–10 mm; stamens 50–80, irregularly grouped; styles 2–4 mm; stigmas capitate. |
Capsules | broadly ovoid to depressed-globose, 4.5–8 × 4–7 mm. |
ovoid to rostrate-subglobose, 3–5 × 2–3 mm. |
Seeds | carinate, 2–2.7 mm; testa coarsely reticulate. |
(0.5–)0.6–0.8(–0.9) mm; testa reticulate. |
2n | = 24. |
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Hypericum sphaerocarpum |
Hypericum virgatum |
|
Phenology | Flowering summer (Jun–Aug). | Flowering mid–late summer (Jun–Sep). |
Habitat | Rocky outcrops or embankments, prairies, stream banks, usually wet or moist, railroad embankments | Dry roadsides, fields, open woods |
Elevation | 500–1000 m (1600–3300 ft) | 0–700 m (0–2300 ft) |
Distribution |
AL; AR; IA; IL; IN; KS; KY; MI; MO; MS; NE; OH; OK; TN; TX; WI; ON
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AL; AR; FL; GA; IL; IN; KY; LA; MD; MS; NC; OH; SC; TN; VA; WV |
Discussion | Hypericum sphaerocarpum differs from H. cistifolium and H. nudiflorum in its semiherbaceous habit and more northwestern distribution, as well as in its combination of relatively long, narrow leaves, persistent sepals, globose and apiculate to rounded capsules, and relatively large seeds. The narrow-leaved, bushy form from eastern parts of the range (var. turgidum) merges with the typical form. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 6, p. 83. | FNA vol. 6, p. 90. |
Parent taxa | Hypericaceae > Hypericum > sect. Myriandra | Hypericaceae > Hypericum > sect. Brathys |
Sibling taxa | ||
Synonyms | Brathydium chamaenerium, B. sphaerocarpum, H. chamaenerium, H. sphaerocarpum var. turgidum, H. turgidum | Brathys lanceolata, H. acutifolium, H. denticulatum subsp. acutifolium, H. denticulatum var. acutifolium, H. denticulatum var. recognitum, H. virgatum var. acutifolium |
Name authority | Michaux: Fl. Bor.-Amer. 2: 78. (1803) | Lamarck: in J. Lamarck et al., Encycl. 4: 158. (1796) |
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