Hypericum crux-andreae

(Linnaeus) Crantz

Inst. Rei Herb. 2: 520. 1766.

Common names: St. Peter’s wort
Basionym: Ascyrum crux-andreae Linnaeus Sp. Pl. 2: 787. 1753
Synonyms: A. cuneifolium Chapman A. grandiflorum Rafinesque A. simplex Zeyher ex Turczaninow A. stans var. obovatum Chapman ex Torrey & A. Gray Hypericoides crux-andreae W. P. Adams & N. Robson Hypericum stans
Treatment appears in FNA Volume 6. Treatment on page 85. Mentioned on page 74, 86, 87.

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.

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


V6 140-distribution-map.jpg

Ala., Ark., Del., D.C., Fla., Ga., Ky., La., Md., Miss., N.J., N.Y., N.C., Okla., Pa., S.C., Tenn., Tex., Va.


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).

Selected References


Lower Taxa

... more about "Hypericum crux-andreae"
Norman K. B. Robson +
(Linnaeus) Crantz +
Ascyrum crux-andreae +
St. Peter’s wort +
Ala. +, Ark. +, Del. +, D.C. +, Fla. +, Ga. +, Ky. +, La. +, Md. +, Miss. +, N.J. +, N.Y. +, N.C. +, Okla. +, Pa. +, S.C. +, Tenn. +, Tex. +  and Va. +
0–1500 m +
Moist to dry, pine savannas and flatwoods, meadows, bogs, other wet habitats, lake and pond margins +
Flowering summer–fall. +
Inst. Rei Herb. +
Endemic +  and Illustrated +
A. cuneifolium +, A. grandiflorum +, A. simplex +, A. stans var. obovatum +, Hypericoides crux-andreae +  and Hypericum stans +
Hypericum crux-andreae +
Hypericum +
species +