Hypericum sphaerocarpum |
Hypericum paucifolium |
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round-fruit St. John's-wort, roundseed 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 annual or perennial, erect or decumbent at base, not rooting, branches basal, relatively few or none, 1–7 dm. |
Stems | internodes 2–4-lined. |
internodes 4-angled. |
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. |
erect to spreading, sessile; blade linear-oblong or linear-lanceolate to linear, 5–33 × 0.5–2 mm, leathery, margins plane to revolute, apex acute, basal veins 1(–3), midrib with (0–)1–3 pairs of branches. |
Inflorescences | rounded-corymbiform, 7–70-flowered, narrowly branched, sometimes with dichasia or branches from to 8 proximal nodes. |
narrowly V-shaped, 1–50-flowered, branching mostly dichasial. |
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. |
10–15 mm diam.; sepals narrowly oblong to narrowly lanceolate, subequal to unequal, 3–7 × 0.8–1.6 mm, margins sometimes ciliate, not setulose-ciliate, apex acute; petals golden yellow to orange-yellow, red-tinged , oblanceolate to obovate, 6–10 mm; stamens 35–50, irregularly 3-fascicled; styles 2.5–5 mm; stigmas broadly capitate. |
Capsules | broadly ovoid to depressed-globose, 4.5–8 × 4–7 mm. |
± narrowly ovoid-conic, 4–9 × 2–4 mm. |
Seeds | carinate, 2–2.7 mm; testa coarsely reticulate. |
0.5–0.7 mm; testa finely linear-scalariform. |
Hypericum sphaerocarpum |
Hypericum paucifolium |
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Phenology | Flowering summer (Jun–Aug). | Flowering spring. |
Habitat | Rocky outcrops or embankments, prairies, stream banks, usually wet or moist, railroad embankments | Dry, grassy habitats, roadsides |
Elevation | 500–1000 m (1600–3300 ft) | 0–50 m (0–200 ft) |
Distribution |
AL; AR; IA; IL; IN; KS; KY; MI; MO; MS; NE; OH; OK; TN; TX; WI; ON
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TX; Mexico |
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.) |
The relatively long styles distinguish Hypericum paucifolium from all other North American species of sect. Trigynobrathys. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 6, p. 83. | FNA vol. 6, p. 95. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Brathydium chamaenerium, B. sphaerocarpum, H. chamaenerium, H. sphaerocarpum var. turgidum, H. turgidum | |
Name authority | Michaux: Fl. Bor.-Amer. 2: 78. (1803) | S. Watson: Proc. Amer. Acad. Arts Sci. 25: 143. (1890) |
Web links |