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round-fruit St. John's-wort, roundseed St. Johnswort

coppery St. John's wort

Habit Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm. Herbs perennial, erect, branching at usually aerenchymatous base and in inflorescence, 2–7 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) spreading to appressed, sessile;

blade usually broadly to narrowly ovate, rarely elliptic or lanceolate, 4–20 × 5–15(–18) mm, mostly shorter than internodes, leathery, margins plane, apex acute to subrounded, densely gland-dotted, basal veins 1–5, if 1, midrib with 2–3 pairs of branches.

Inflorescences

rounded-corymbiform, 7–70-flowered, narrowly branched, sometimes with dichasia or branches from to 8 proximal nodes.

broadly pyramidal to corymbiform, to 25-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.

5–13 mm diam.;

sepals ovate or lanceolate to elliptic or obovate, subequal, 3–8 × 1.5–4 mm, margins sometimes ciliate, not setulose-ciliate, apex acute;

petals orange-yellow, obovate, 5–10 mm;

stamens 50–80, irregularly grouped;

styles 2–4 mm;

stigmas clavate.

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.

0.4–0.7 mm;

testa obscurely linear-reticulate to finely ribbed-scalariform.

Hypericum sphaerocarpum

Hypericum denticulatum

Phenology Flowering summer (Jun–Aug). Flowering summer–early fall (Jun–Sep).
Habitat Rocky outcrops or embankments, prairies, stream banks, usually wet or moist, railroad embankments Wet woods, marshes, bogs
Elevation 500–1000 m (1600–3300 ft) 0–400 m (0–1300 ft)
Distribution
from FNA
AL; AR; IA; IL; IN; KS; KY; MI; MO; MS; NE; OH; OK; TN; TX; WI; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; DE; GA; NC; NJ; NY; PA; SC; TN; VA
[WildflowerSearch map]
[BONAP county map]
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.)

D. H. Webb (1980) regarded the disjunct populations in North Carolina and Tennessee as possible relicts and the Alabama one as due to recent introduction. J. R. Allison (2011) agreed and, in his opinion, the Pennsylvania and Virginia records are historical, and Hypericum denticulatum is likely adventive in Georgia.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 6, p. 83. FNA vol. 6, p. 89.
Parent taxa Hypericaceae > Hypericum > sect. Myriandra Hypericaceae > Hypericum > sect. Brathys
Sibling taxa
H. adpressum, H. anagalloides, H. apocynifolium, H. ascyron, H. boreale, H. brachyphyllum, H. buckleyi, H. canadense, H. canariense, H. chapmanii, H. cistifolium, H. concinnum, H. crux-andreae, H. cumulicola, H. densiflorum, H. denticulatum, H. dolabriforme, H. drummondii, H. edisonianum, H. ellipticum, H. erythreae, H. fasciculatum, H. frondosum, H. galioides, H. gentianoides, H. graveolens, H. gymnanthum, H. harperi, H. hypericoides, H. kalmianum, H. lissophloeus, H. lloydii, H. lobocarpum, H. maculatum, H. majus, H. microsepalum, H. mutilum, H. myrtifolium, H. nitidum, H. nudiflorum, H. paucifolium, H. perforatum, H. prolificum, H. pseudomaculatum, H. punctatum, H. radfordiorum, H. scouleri, H. setosum, H. suffruticosum, H. tenuifolium, H. tetrapetalum, H. virgatum, H. ×mitchellianum
H. adpressum, H. anagalloides, H. apocynifolium, H. ascyron, H. boreale, H. brachyphyllum, H. buckleyi, H. canadense, H. canariense, H. chapmanii, H. cistifolium, H. concinnum, H. crux-andreae, H. cumulicola, H. densiflorum, H. dolabriforme, H. drummondii, H. edisonianum, H. ellipticum, H. erythreae, H. fasciculatum, H. frondosum, H. galioides, H. gentianoides, H. graveolens, H. gymnanthum, H. harperi, H. hypericoides, H. kalmianum, H. lissophloeus, H. lloydii, H. lobocarpum, H. maculatum, H. majus, H. microsepalum, H. mutilum, H. myrtifolium, H. nitidum, H. nudiflorum, H. paucifolium, H. perforatum, H. prolificum, H. pseudomaculatum, H. punctatum, H. radfordiorum, H. scouleri, H. setosum, H. sphaerocarpum, H. suffruticosum, H. tenuifolium, H. tetrapetalum, H. virgatum, H. ×mitchellianum
Synonyms Brathydium chamaenerium, B. sphaerocarpum, H. chamaenerium, H. sphaerocarpum var. turgidum, H. turgidum H. angulosum, H. denticulatum var. ovalifolium, H. laevigatum, H. virgatum var. ovalifolium
Name authority Michaux: Fl. Bor.-Amer. 2: 78. (1803) Walter: Fl. Carol., 190. (1788)
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