Flora of North America species comparison

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Hypericum perforatum

Hypericum dolabriforme

Chase-devil, common St. John's-wort, Klamath weed, millepertuis commun, Tipton's weed

straggling St. John's-wort
Habit Subshrubs, decumbent and woody (not rooting) at base, branching at base or throughout, 1.5–5 dm, bark thin.
Stems

internodes 4-lined at first, then 2-lined to terete.
Leaf

blades linear-elliptic or linear-oblong to linear, 20–35 × 3–5 mm (main stem), base not articulated, narrowly cuneate to rounded, margins recurved to revolute, apex obtuse to acute, midrib unbranched.
Inflorescences

obconic, (1–)3–20-flowered, ± widely branched, sometimes with single flowers at immediately proximal nodes.
Flowers

15–20 mm diam.;

sepals persistent, not enclosing capsule, 5, ovate-lanceolate to lanceolate, ± foliaceous, unequal, 5–8(–15) × 2–3(–8)mm;

petals 5, yellow, curved-dolabriform, 10–13 mm;

stamens deciduous, 120–200;

ovary 3-merous.
Capsules

ovoid-conic, rostrate, 4–9 × 3–4 mm.
Seeds

carinate, 1.5–1.8 mm;

testa reticulate-scalariform.
2n

= 18.

Hypericum perforatum

Hypericum dolabriforme
Phenology Flowering summer (Jun–Sep).
Habitat Limestone outcrops, cedar glades, dry, rocky stream beds
Elevation 0–500 m [0–1600 ft]
Distribution
from FNA
AR; CA; CO; CT; DC; DE; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; VA; VT; WA; WI; WV; WY; BC; MB; NB; NF; NS; ON; PE; QC; Europe; Asia (sw Arabia, China, India, Mongolia, Siberia); n Africa [Also introduced widely elsewhere]
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; GA; IN; KY; TN
[BONAP county map]
Discussion

Subspecies 4 (1 in the flora).

Hypericum perforatum has been introduced into various parts of the world, including North America, where only subsp. perforatum is represented. The range of variation in the flora area is less than occurs in Europe, and signs of hybridization that are common there are absent in North America.

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

Hypericum dolabriforme is superficially similar to H. sphaerocarpum, to which W. P. Adams (1962) related it. Apart from the narrow leaves and unequal sepals, it is much nearer morphologically to H. myrtifolium (for example, in the wide-spreading inflorescence, numbers of stamens, and ovoid-conic capsules). Hypericum bissellii, described from a plant growing in Southington, Connecticut, is unlikely to be indigenous in that state.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 6, p. 99. Treatment author: Norman K. B. Robson. FNA vol. 6, p. 84. Treatment author: Norman K. B. Robson.
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. 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. 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
Subordinate taxa
H. perforatum subsp. perforatum
Synonyms Brathydium dolabriforme, H. bissellii, H. procumbens
Name authority Linnaeus: Sp. Pl. 2: 785. (1753) Ventenat: Descr. Pl. Nouv., plate 45. (1801)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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