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orange-grass, orange-grass St. John's-wort, pineweed, pinweed St. Johnswort

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

Habit Herbs annual, erect, branches strict, in distal 2/3 or from most nodes, 0.7–6 dm, wiry. 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

appressed, sessile;

blade narrowly triangular-subulate to linear-subulate, scalelike, 1–4 × 0.4–0.6 mm, subcoriaceous to chartaceous, margins incurved, apex obtuse to rounded, basal vein 1, midrib unbranched.

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

usually pyramidal, 1–24-flowered, branching mostly monochasial.

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

Flowers

3–5 mm diam.;

sepals lanceolate to narrowly oblong or linear-lanceolate, unequal, 1.5–2.5 × 0.4–0.8 mm, apex acute;

petals orange-yellow to golden yellow, oblong, 2–4 mm;

stamens 5–11, 5 separate or obscurely 5-grouped;

styles 0.8–1.2 mm;

stigmas broadly 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

narrowly cylindric-conic, 4–5 × 1–1.2 mm, length 2–2.7 times sepals.

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

Seeds

0.4–0.8 mm;

testa markedly ribbed-scalariform.

0.5–0.6 mm;

testa finely linear-scalariform.

2n

= 24.

= 16.

Hypericum gentianoides

Hypericum gymnanthum

Phenology Flowering late spring–fall (May–Oct). Flowering summer (Jun–Sep).
Habitat Dry, sandy soil in open woods, fields, roadsides, waste or rocky places, tall-grass prairie Bogs, ditches, open and cleared woods, damp habitats
Elevation 0–500 m (0–1600 ft) 0–400 m (0–1300 ft)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NS; ON; PE [Introduced in West Indies (Dominican Republic), South America (Brazil, Paraguay), Europe (France)]
[WildflowerSearch map]
[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 gentianoides is smaller in all parts than H. drummondii and more branched. The relatively long, narrow capsule is diagnostic, as are the relatively small, often scalelike leaves.

Hypericum sarothra Michaux and Sarothra hypericoides Nuttall are illegitimate names that pertain here.

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

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. 95. 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. 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
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 Sarothra gentianoides, Brathys gentianoides, H. nudicaule H. canadense var. cardiophyllum, H. mutilum var. gymnanthum, Sarothra gymnantha
Name authority (Linnaeus) Britton: Prelim. Cat., 9. (1888) Engelmann & A. Gray: Boston J. Nat. Hist. 5: 212. (1845)
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