Hypericum sphaerocarpum |
Hypericum nitidum |
|||||
---|---|---|---|---|---|---|
round-fruit St. John's-wort, roundseed St. Johnswort |
Carolina St. Johnswort |
|||||
Habit | Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm. | Shrubs, erect, forming dense thickets, 3–45 dm, bark smooth, not metallic-silvery. | ||||
Stems | internodes 2–4-lined. |
internodes 4-lined at first, becoming 2-winged, then terete. |
||||
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 or linear-subulate, 9–26 × 0.5–1.5 mm, base articulated, narrowly cuneate or parallel, margins revolute, apex rounded or acute to long-acuminate with prominent hydathode, midrib unbranched. |
||||
Inflorescences | rounded-corymbiform, 7–70-flowered, narrowly branched, sometimes with dichasia or branches from to 8 proximal nodes. |
narrowly to broadly cylindric, 3–15-flowered, sometimes with 1–3(–7)-flowered dichasia from to 6 proximal nodes, sometimes with 1–2 pairs of additional flowering branches. |
||||
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. |
10–18 mm diam.; sepals deciduous, not enclosing capsule, 5, linear-subulate, unequal to subequal, 3.5–7 × 0.4–0.8 mm; petals 5, yellow, obovate to elliptic-lanceolate, (5–)6–10 mm; stamens deciduous, 50–80(–115); ovary 3-merous; styles shorter than ovaries. |
||||
Capsules | broadly ovoid to depressed-globose, 4.5–8 × 4–7 mm. |
narrowly conic to cylindric, (4.5–)5–7 × (1.3–)2–3 mm. |
||||
Seeds | carinate, 2–2.7 mm; testa coarsely reticulate. |
scarcely carinate, 0.5 mm; testa finely reticulate. |
||||
Hypericum sphaerocarpum |
Hypericum nitidum |
|||||
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
|
AL; FL; GA; NC; SC; West Indies (Cuba); Central America (Belize)
|
||||
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). The two subspecies of Hypericum nitidum present in North America apparently remain distinct there; the distinctions are less clear in Cuba, where subsp. cubense (Turczaninow) N. Robson is also present. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||
Key |
|
|||||
Source | FNA vol. 6, p. 83. | FNA vol. 6, p. 79. | ||||
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 | Myriandra nitida | ||||
Name authority | Michaux: Fl. Bor.-Amer. 2: 78. (1803) | Lamarck: in J. Lamarck et al., Encycl. 4: 160. (1797) | ||||
Web links |