Hypericum sphaerocarpum |
Hypericum lissophloeus |
|
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round-fruit St. John's-wort, roundseed St. Johnswort |
smooth-bark St. John's wort |
|
Habit | Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm. | Shrubs, erect, sparsely branched, forming dense clumps sometimes with prop roots, to 40 dm, bark smooth and metallic-silvery, without laticifers, exfoliating in thin, curled plates. |
Stems | internodes 2–4-lined. |
internodes 4-lined at first, soon 4-angled, then terete, dull silvery, glaucous. |
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 linear-subulate to acicular, (9–)12–17 × 0.5–0.8 mm, glaucous, base articulated, parallel or almost so, margins revolute, apex obtuse to rounded, midrib unbranched. |
Inflorescences | rounded-corymbiform, 7–70-flowered, narrowly branched, sometimes with dichasia or branches from to 8 proximal nodes. |
narrowly cylindric, 1–3-flowered, usually with paired flowers or triads from to 9 proximal nodes. |
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. |
20 mm diam.; sepals deciduous, not enclosing capsule, 5, linear-subulate, subequal, 7–8 × 0.5–0.8 mm, glaucous; petals 5, bright yellow, obovate-spatulate, 10–12 mm; stamens deciduous, 170–220; ovary 3-merous; styles 5 mm. |
Capsules | broadly ovoid to depressed-globose, 4.5–8 × 4–7 mm. |
narrowly ovoid to ellipsoid, 6–7 × 2.5–3.5 mm. |
Seeds | carinate, 2–2.7 mm; testa coarsely reticulate. |
narrowly carinate, 1–1.6 mm; testa coarsely reticulate-sulcate. |
2n | = 18. |
|
Hypericum sphaerocarpum |
Hypericum lissophloeus |
|
Phenology | Flowering summer (Jun–Aug). | Flowering summer–early fall (Jun–Oct). |
Habitat | Rocky outcrops or embankments, prairies, stream banks, usually wet or moist, railroad embankments | Pond and lake margins to 1.5 m deep water |
Elevation | 500–1000 m (1600–3300 ft) | 0–10 m (0–0 ft) |
Distribution |
AL; AR; IA; IL; IN; KS; KY; MI; MO; MS; NE; OH; OK; TN; TX; WI; ON
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FL |
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.) |
Of conservation concern. Hypericum lissophloeus is found in Bay and Washington counties. The larger capsules, one- to three-flowered, lateral inflorescence branches, and smooth-polished, metallic bark (that exfoliates like that of Betula species) are among the features that distinguish H. lissophloeus from H. fasciculatum, H. nitidum, and their allies (H. brachyphyllum and H. chapmanii). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 6, p. 83. | FNA vol. 6, p. 80. |
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) | W. P. Adams: Contr. Gray Herb. 189: 21. (1962) |
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