Hypericum sphaerocarpum |
Hypericum hypericoides |
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round-fruit St. John's-wort, roundseed St. Johnswort |
St. Andrew's cross |
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Habit | Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm. | Subshrubs or shrubs, erect or decumbent to prostrate, unbranched or branched, sometimes diffuse and mat-forming, 0.5–3 or 3–15 dm. | ||||
Stems | internodes 2–4-lined. |
internodes 2-winged. |
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Leaf | 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. |
blades oblanceolate or narrowly oblong or elliptic to linear, 7–25 × 1–8.5 mm, base not articulated, usually cuneate, sometimes rounded, with glandlike auricles, margins subrecurved, apex rounded to obtuse, midrib with 1–2 pairs of branches. |
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Inflorescences | rounded-corymbiform, 7–70-flowered, narrowly branched, sometimes with dichasia or branches from to 8 proximal nodes. |
narrowly cylindric to pyramidal, 1–12-flowered from 1–4 nodes, sometimes with branches from to 10 proximal nodes, or branching more elaborate and pseudodichotomous; pedicels erect in fruit, bracteoles distal. |
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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. |
10–20 mm diam.; sepals persistent, enclosing capsule, 4, unequal, outer ovate-suborbiculate to narrowly elliptic, 5–12.5 × 2–13 mm, apex subapiculate to obtuse, inner lanceolate, 1–4 × 2 mm, apex acute; petals 4, bright to pale yellow, obovate to narrowly oblong-elliptic, 6–12 mm; stamens persistent, 40–50; ovary 2-merous. |
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Capsules | broadly ovoid to depressed-globose, 4.5–8 × 4–7 mm. |
narrowly compressed-ovoid to cylindric-ellipsoid, 5–9 × 2–4 mm. |
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Seeds | carinate, 2–2.7 mm; testa coarsely reticulate. |
not carinate, 0.6–0.8 mm; testa finely linear-reticulate to linear-foveolate. |
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Hypericum sphaerocarpum |
Hypericum hypericoides |
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Phenology | Flowering summer (Jun–Aug). | |||||
Habitat | Rocky outcrops or embankments, prairies, stream banks, usually wet or moist, railroad embankments | |||||
Elevation | 500–1000 m (1600–3300 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; DC; DE; FL; GA; IL; IN; KS; KY; LA; MA; MD; MO; MS; NC; NJ; NY; OH; OK; PA; SC; TN; TX; VA; WV; Mexico; West Indies (Bahamas, Greater Antilles); Bermuda; Central America (Guatemala, Honduras)
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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.) |
Subspecies 3 (2 in the flora). Hypericum hypericoides can be distinguished from H. crux-andreae by the two-merous ovary, narrower leaves, smaller flowers, and more richly-branched stems. It is variable in leaf and sepal shape and size; three subspecies can be recognized. The erect bushy form (subsp. hypericoides) is most widespread and has given rise to a northern diffuse form (subsp. multicaule) in the United States and a prostrate form (subsp. prostratum N. Robson) in Hispaniola. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 6, p. 83. | FNA vol. 6, p. 87. | ||||
Parent taxa | Hypericaceae > Hypericum > sect. Myriandra | Hypericaceae > Hypericum > sect. Myriandra | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Brathydium chamaenerium, B. sphaerocarpum, H. chamaenerium, H. sphaerocarpum var. turgidum, H. turgidum | Ascyrum hypericoides | ||||
Name authority | Michaux: Fl. Bor.-Amer. 2: 78. (1803) | (Linnaeus) Crantz: Inst. Rei Herb. 2: 520. (1766) | ||||
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