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

imperforate St. John's wort, spotted St. John's-wort, streaked St. John's-wort

Habit Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm.
Stems

internodes 2–4-lined.

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.

Inflorescences

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

Capsules

broadly ovoid to depressed-globose, 4.5–8 × 4–7 mm.

Seeds

carinate, 2–2.7 mm;

testa coarsely reticulate.

Hypericum sphaerocarpum

Hypericum maculatum

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
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
ID; WA; BC; Europe; Asia (Siberia)
[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.)

Subspecies 3 (1 in the flora).

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

Source FNA vol. 6, p. 83. FNA vol. 6, p. 99.
Parent taxa Hypericaceae > Hypericum > sect. Myriandra Hypericaceae > Hypericum > sect. Hypericum
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. 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. 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
Subordinate taxa
H. maculatum subsp. obtusiusculum
Synonyms Brathydium chamaenerium, B. sphaerocarpum, H. chamaenerium, H. sphaerocarpum var. turgidum, H. turgidum
Name authority Michaux: Fl. Bor.-Amer. 2: 78. (1803) Crantz: Stirp. Austr. Fasc. 2: 64. (1763)
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