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

Apalachicola St. Johnswort

Habit Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm. Shrubs, erect, treelike, to 40 dm, bark thick-corky, striate, exfoliating in thin, papery sheets or plates.
Stems

internodes 2–4-lined.

internodes 4-lined at first, soon 4-angled, then terete, not 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, 8–25 × 0.5–0.7 mm, not glaucous, base articulated, parallel or slightly expanded, margins revolute, apex acute, midrib unbranched.

Inflorescences

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

shortly cylindric, 1–3-flowered, often with single flowers or triads from 1–2 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.

12–15 mm diam.;

sepals deciduous, not enclosing capsule, 5, linear-subulate, unequal, 5–7 × 0.5 mm, not glaucous;

petals 5, bright yellow, oblong-spatulate, 7–9 mm;

stamens deciduous, 75;

ovary 3-merous;

styles 2.5–4 mm.

Capsules

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

narrowly pyramidal-ovoid, 6 × 2.4 mm.

Seeds

carinate, 2–2.7 mm;

testa coarsely reticulate.

not carinate, 0.6–0.8 mm;

testa finely foveolate-reticulate.

Hypericum sphaerocarpum

Hypericum chapmanii

Phenology Flowering summer (Jun–Aug). Flowering summer (Jun–Aug).
Habitat Rocky outcrops or embankments, prairies, stream banks, usually wet or moist, railroad embankments Pond margins, flatwoods, depressions
Elevation 500–1000 m (1600–3300 ft) 0–10 m (0–0 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
FL
[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.)

Hypericum chapmanii differs from H. fasciculatum in its taller, single-stemmed habit, thicker stems (to 10–15 cm diameter) with fluted, spongy bark containing large laticifers, and fewer-flowered inflorescences.

Hypericum chapmanii is known from the panhandle of northwestern Florida.

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

Source FNA vol. 6, p. 83. FNA vol. 6, p. 81.
Parent taxa Hypericaceae > Hypericum > sect. Myriandra Hypericaceae > Hypericum > sect. Myriandra
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. 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. 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. arborescens
Name authority Michaux: Fl. Bor.-Amer. 2: 78. (1803) W. P. Adams: Contr. Gray Herb. 189: 22. (1962)
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