The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

spotted St. John's-wort

Carolina St. Johnswort

Habit Herbs erect to ascending, with rarely rooting, branching base, 1.3–10.5 dm. Shrubs, erect, forming dense thickets, 3–45 dm, bark smooth, not metallic-silvery.
Stems

clustered, internodes not lined, with black glands scattered all over.

internodes 4-lined at first, becoming 2-winged, then terete.

Leaves

spreading or ascending, usually sessile, rarely petiolate (to 1 mm);

blade elliptic or oblong to lanceolate or triangular-lanceolate, or oblanceolate, 14–40(–58) × 3–17(–22.5) mm, base cordate to narrowly cuneate, margins plane, apex usually rounded to retuse, rarely acute to obtuse, midrib with 3–5 pairs of branches, tertiary veins densely reticulate toward margins, black glands intramarginal (dense) and laminar (scattered).

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

subcorymbiform to cylindric, 10–206(–600)-flowered, subsidiary branches narrowly ascending to curved-ascending.

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

8–15 mm diam.;

sepals not imbricate, erect in fruit, lanceolate or oblong-lanceolate to elliptic or ovate-elliptic, subequal, (1.5–)2–4 × 0.8–1.6 mm, apex acute to rounded;

petals pale yellow, oblanceolate to elliptic, 3–6(–9) mm;

stamens (20–)30–60;

anther gland black;

styles 1–4 mm.

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

ovoid to subglobose, 2.5–6 × 2–3.5(–4) mm, with longitudinal vittae or elongate to ovoid vesicles.

narrowly conic to cylindric, (4.5–)5–7 × (1.3–)2–3 mm.

Seeds

not carinate, 0.5–0.7 mm;

testa linear-reticulate.

scarcely carinate, 0.5 mm;

testa finely reticulate.

2n

= 14, 16.

Hypericum punctatum

Hypericum nitidum

Phenology Flowering summer (May–Sep).
Habitat Open or slightly shaded, dry to marshy habitats
Elevation 50–1200 m (200–3900 ft)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NF; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; NC; SC; West Indies (Cuba); Central America (Belize)
[WildflowerSearch map]
[BONAP county map]
Discussion

Hypericum punctatum has been confused with H. pseudomaculatum; it can almost always be distinguished by style length and anther gland (black in H. punctatum, amber or pellucid in H. pseudomaculatum). D. E. Culwell’s (1970) record of one specimen of the latter from Missouri with a black anther gland could refer to a hybrid; he and other authors agree that such plants are rare, despite the considerable overlap in distribution of these species. Culwell remarked on the unexpected fecundity of the experimentally produced cross H. graveolens × punctatum but nowhere compared the resulting plants with H. ×mitchellianum, a probable hybrid with that parentage (see discussion

under H. ×mitchellianum. Both H. punctatum and H. ×mitchellianum (but not H. graveolens) display a ring of 16 chromosomes at meiosis, and Culwell suggested that this phenomenon may imply some degree of pseudogamy in the group. C. R. Bell (1965) recorded n = 7 chromosomes for this species; his illustration shows n = 8.

(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
1. Plants to 45+ dm, with ± numerous, stout, bushy-branched stems from base; leaf blade margins loosely inrolled, apex obtuse to rounded-apiculate; sepal apices shortly apiculate to acute.
subsp. nitidum
1. Plants 3–10 dm, with ± few, slender, little-branched stems from base; leaf blade margins tightly inrolled, apex acute to long-acuminate; sepal apices acute to long-acuminate.
subsp. exile
Source FNA vol. 6, p. 101. FNA vol. 6, p. 79.
Parent taxa Hypericaceae > Hypericum > sect. Hypericum 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. radfordiorum, H. scouleri, H. setosum, H. sphaerocarpum, 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. maculatum, H. majus, H. microsepalum, H. mutilum, H. myrtifolium, 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. nitidum subsp. exile, H. nitidum subsp. nitidum
Synonyms H. maculatum var. corymbosum, H. maculatum var. heterophyllum, H. maculatum var. subcordifolium, H. maculatum var. subpetiolatum, H. micranthum, H. subpetiolatum Myriandra nitida
Name authority Lamarck: in J. Lamarck et al., Encycl. 4: 164. (1797) Lamarck: in J. Lamarck et al., Encycl. 4: 160. (1797)
Web links