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Atlantic St. Peter's-wort, St. Peter's wort

Habit Shrubs, usually erect to suberect, rarely decumbent and rooting, usually unbranched, rarely sparsely branched distally, 1–13.5 dm.
Stems

internodes 2–4-lined at first, then 2-winged.

Leaf

blades usually oblong to elliptic, rarely obovate to oblanceolate or triangular-ovate, 12–36 × 6–16 mm, base articulated, rounded to slightly cordate-amplexicaul, without glandlike auricles, margins plane to subrecurved, apex rounded to obtuse, midrib with to 3 pairs of branches.

Inflorescences

± narrowly cylindric to narrowly pyramidal, 1–3(–7)-flowered, branching dichasial, from to 4 proximal nodes.

Flowers

20–30 mm diam.;

sepals persistent, enclosing capsule, 4, unequal, outer broadly ovate to circular, 9–20 × 9–18 mm, apex apiculate or obtuse to rounded, inner narrowly elliptic to lanceolate, 7–14 × 2–4 mm, apex acute to subacute;

petals 4, bright yellow, obovate, 11–18 mm;

stamens persistent, 80–100;

ovary 3(–4)-merous.

Capsules

narrowly ellipsoid-ovoid, 7–10 × 5–6.5 mm.

Seeds

not carinate, 0.8 mm;

testa shallowly scalariform.

2n

= 18.

Hypericum crux-andreae

Phenology Flowering summer–fall.
Habitat Moist to dry, pine savannas and flatwoods, meadows, bogs, other wet habitats, lake and pond margins
Elevation 0–1500 m (0–4900 ft)
Distribution
from FNA
AL; AR; DC; DE; FL; GA; KY; LA; MD; MS; NC; NJ; NY; OK; PA; SC; TN; TX; VA
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Discussion

Hypericum crux-andreae, long known as Ascyrum stans, is a derivative of H. frondosum in which the tetramerous tendency in the perianth has become fixed. The low, multistemmed form with cuneate leaves, longer-

pedicellate flowers, and shorter sepals (A. cuneifolium, A. stans var. obovatum) cannot be separated from typical H. crux-andreae.

Linnaeus included “Hypericum ex terra mariana, floribus exiguis luteis” under his phrase name for Ascyrum crux-andreae; that element of the protologue refers to H. mutilum Linnaeus; see N. K. B. Robson (1980).

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

Source FNA vol. 6, p. 85.
Parent taxa Hypericaceae > Hypericum
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. 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 Ascyrum crux-andreae, A. cuneifolium, A. grandiflorum, A. simplex, A. stans var. obovatum, Hypericoides crux-andreae, H. stans
Name authority (Linnaeus) Crantz: Inst. Rei Herb. 2: 520. (1766)
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