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brushy mountain St. Johnswort

claspingleaf St. Johnswort, small-flower St. John's wort

Habit Herbs perennial, erect or ± spreading, branching at base and beyond, (3–)4–7(–7.8) dm. Herbs annual, usually erect, sometimes shortly decumbent and rooting, basal branches none, rarely with 1–3(–6) pairs of narrowly ascending branches distally, 0.6–7 dm.
Stems

internodes 4-lined.

internodes 4-angled.

Leaves

ascending to widely spreading, sessile;

blade narrowly lanceolate (linear-lanceolate on axillary branches), 10–40(–55) × 5–10(–13) mm, longer than internodes, leathery, margins plane, apex acute to acuminate, densely gland-dotted, basal vein 1, midrib with inconspicuous branches.

spreading, sessile or amplexicaul;

blade usually ovate-triangular to broadly ovate, rarely oblong (mid and distal blades lanceolate-deltate), 5–25 × 3–12 mm, papery to membranous, margins plane, apex usually subacute, basal veins (3–)5, midrib usually with 1–2 pairs of branches.

Inflorescences

cylindric, to 40-flowered; branching mostly dichasial, subsidiary branches usually with relatively smaller leaves.

laxly corymbiform to cylindric, (1–)5–65-flowered, branching mostly dichasial.

Flowers

8–15+ mm diam.;

sepals lanceolate, unequal (outer slightly wider than inner), 3–6(–7.5) × 1.1–1.8(–2.2) mm, margins sometimes ciliate, not setulose-ciliate, apex acute or acuminate;

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

stamens 50–80, filaments basally connate;

styles 2–4 mm;

stigmas capitate.

4.5–7 mm diam.;

sepals lanceolate to narrowly ovate, equal, 3–5 × 0.8–1.2 mm, margins sometimes ciliate, not setulose-ciliate, apex acute to acuminate;

petals bright yellow, oblanceolate, 2–4 mm;

stamens 10–14, scarcely grouped;

styles 0.5–0.7 mm;

stigmas broadly capitate.

Capsules

ovoid, 5 × 3–4 mm.

narrowly conic-ellipsoid, 3–5 × 1.5–2 mm, usually broadest at or near middle.

Seeds

0.4–0.8 mm;

testa linear-pitted.

0.5–0.6 mm;

testa finely linear-scalariform.

2n

= 24.

= 16.

Hypericum radfordiorum

Hypericum gymnanthum

Phenology Flowering late spring–fall (May–)Jun–Sep(–Oct). Flowering summer (Jun–Sep).
Habitat Granitic outcrops Bogs, ditches, open and cleared woods, damp habitats
Elevation 500–800 m (1600–2600 ft) 0–400 m (0–1300 ft)
Distribution
from FNA
NC
[BONAP county map]
from FNA
AL; AR; DE; FL; GA; IL; IN; LA; MD; MO; MS; NC; NJ; OH; PA; SC; TN; TX; VA; Central America (Guatemala) [Introduced Atlantic Islands (Azores)]
[WildflowerSearch map]
[BONAP county map]
Discussion

Hypericum gymnanthum was introduced into Poland; it is now extinct there. It is closely related to H. mutilum; it differs from that species in the broader, usually deltate leaves; fewer, stricter branches; no condensed apical stem internode; and larger flowers with lanceolate to ovate sepals.

Hybrids of Hypericum gymnanthum with H. mutilum have been reported from Maryland, Mississippi, North Carolina, Tennessee, and West Virginia, and, perhaps erroneously, with H. canadense from Virginia.

Hypericum gymnanthum has clearly been introduced (recently?) into the Azores, not necessarily by man. Seeds may well have been carried there by birds.

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

Source FNA vol. 6, p. 90. FNA vol. 6, p. 93.
Parent taxa Hypericaceae > Hypericum > sect. Brathys 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. 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. 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 H. canadense var. cardiophyllum, H. mutilum var. gymnanthum, Sarothra gymnantha
Name authority Weakley ex J. R. Allison: Castanea 76: 110, fig. 3. (2011) Engelmann & A. Gray: Boston J. Nat. Hist. 5: 212. (1845)
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