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

millepertuis, St. Andrew's cross, St. John's-wort

Habit Herbs (perennial) or subshrubs, erect or decumbent, not or rarely rhizomatous, unbranched or branched proximally, 2–6 dm. Herbs, annual or perennial, subshrubs, or shrubs [trees], sometimes rhizomatous, glabrous or hairy, with glandular canals, lacunae, or dots containing resins or waxes (amber), essential oils (pale, translucent), and/or, sometimes, hypericin and pseudohypericin (black or red) in various parts.
Stems

internodes 2–4-lined.

internodes terete (not lined) or 2-, 4-, or 6-lined at first (lines usually raised), then sometimes becoming angled, terete, or winged;

bark smooth or striate, sometimes corky, punctiform.

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.

terminal, cymose, 2+-flowered, or flowers solitary, branching stellate [cupulate];

sepals persistent or deciduous, (3–)4–5, distinct or ± connate, margins sometimes glandular-ciliate;

petals persistent or deciduous, (3–)4–5[–6], contorted, yellow to orange, sometimes red-tinged;

stamens persistent or deciduous, (5–)10–300(–650), in continuous or interrupted ring or in (3–)4–5 fascicles, fascicles distinct or connate, each with 1–60+ stamens;

filaments distinct or basally connate;

anthers yellow to orange, oblong to ellipsoid, almost isodiametric, sometimes with amber or black gland on connective;

staminode fascicles 0 [3];

ovary 2–5-merous;

placentation axile to parietal;

ovules 2+ on each placenta;

styles distinct or ± connate basally, spreading to ± appressed.

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.

2–5-valved, sometimes with glandular vittae or vesicles.

Seeds

carinate, 2–2.7 mm;

testa coarsely reticulate.

narrowly cylindric to ellipsoid, sometimes carinate;

testa foveolate or reticulate to scalariform [papillose].

x

= 12, 9–7, 6 (dihaploid).

Hypericum sphaerocarpum

Hypericum

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 USDA
Nearly worldwide
[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.)

Species ca. 490 (54 in the flora).

Shrubs with deciduous leaves, petals, and stamens belong to either Hypericum sect. Ascyreia Choisy (with five stamen fascicles and five styles) or sect. Androsaemum (Duhamel) Godron (with five stamen fascicles and three or four styles). These are all introductions, mostly garden escapes. Those in sect. Ascyreia include: Hypericum calycinum Linnaeus, a low shrub with creeping stolons and flowers 50–95 mm diam. that has been found in California, Oregon, and Washington; H. ×moserianum Luquet ex André, its hybrid with H. patulum Thunberg, a low (sterile?) branching shrub with red anthers; and H. hookerianum Wight & Arnott, a shrub to 2 m tall with narrow leaves and a dense ring of relatively short stamens, recorded from California (its identity requires confirmation). In sect. Androsaemum, H. androsaemum is a deciduous shrub with relatively small flowers and baccate fruits that ripen from cherry-red to black; it has been found in British Columbia and in California and Washington.

Introduced herbaceous species with three stamen fascicles and three styles include: Hypericum hirsutum, with hairy stems and leaves (Ontario); H. tetrapterum, with four-winged internodes and lanceolate sepals (British Columbia and Washington); H. pulchrum with cordate leaves and red-tinged petals (Newfoundland, St. Pierre and Miquelon); and H. humifusum Linnaeus, a procumbent herb with unequal sepals (British Columbia).

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

Key
1. Herbs, subshrubs, or shrubs, black glands absent; stamens in continuous or interrupted ring or in 4 or 5 barely discernable fascicles, each of 1 or 2 stamens
→ 2
1. Herbs or shrubs, black and/or red glands usually present throughout, sometimes absent; stamens in 5 fascicles, each of 2+ stamens
→ 3
2. Herbs (perennial), subshrubs, or shrubs; petals deciduous; stamens usually persistent, sometimes deciduous, 30–650, in continuous ring or in 4–5 barely discernable fascicles; styles ± appressed, bases distinct.
sect. Myriandra
2. Herbs (annual or perennial); petals persistent; stamens persistent, (5–)10–80, usually in continuous or interrupted ring, sometimes in 5 barely discernable fascicles; styles ± spreading, bases distinct.
Hypericum informal sect. group Brathys
3. Shrubs; leaves deciduous (base articulated); style bases distinct.
sect. Webbia
3. Herbs (perennial); leaves persistent or tardily deciduous (base not articulated) or; style bases ± connate or distinct
→ 4
4. Herbs, black glands absent; flowers 40–70 mm diam.; stamens 150, in 5 fascicles, fascicles usually distinct, rarely 1 pair connate; styles ± appressed, bases ± connate or distinct.
sect. Roscyna
4. Herbs, black glands usually on leaves, sepals, and petals and, sometimes, on stems and anthers; flowers 6–35 mm diam.; stamens 20–109, in 5 fascicles, fascicles connate (as 2 + 2 + 1); styles spreading, bases distinct.
Hypericum informal sect. group Hypericum
Source FNA vol. 6, p. 83. FNA vol. 6, p. 72. Author: Norman K. B. Robson.
Parent taxa Hypericaceae > Hypericum > sect. Myriandra Hypericaceae
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
Subordinate taxa
H. sect. Myriandra, H. sect. Roscyna, H. sect. Webbia
Synonyms Brathydium chamaenerium, B. sphaerocarpum, H. chamaenerium, H. sphaerocarpum var. turgidum, H. turgidum Ascyrum, Crookea, Sanidophyllum, Sarothra
Name authority Michaux: Fl. Bor.-Amer. 2: 78. (1803) Linnaeus: Sp. Pl. 2: 783. (1753): Gen. Pl. ed. 5, 341. (1754)
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