Flora of North America species comparison

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Hypericum perforatum

Hypericum chapmanii

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

Apalachicola St. Johnswort
Habit Shrubs, erect, treelike, to 40 dm, bark thick-corky, striate, exfoliating in thin, papery sheets or plates.
Stems

internodes 4-lined at first, soon 4-angled, then terete, not glaucous.
Leaf

blades linear-subulate, 8–25 × 0.5–0.7 mm, not glaucous, base articulated, parallel or slightly expanded, margins revolute, apex acute, midrib unbranched.
Inflorescences

shortly cylindric, 1–3-flowered, often with single flowers or triads from 1–2 proximal nodes.
Flowers

12–15 mm diam.;

sepals deciduous, not enclosing capsule, 5, linear-subulate, unequal, 5–7 × 0.5 mm, not glaucous;

petals 5, bright yellow, oblong-spatulate, 7–9 mm;

stamens deciduous, 75;

ovary 3-merous;

styles 2.5–4 mm.
Capsules

narrowly pyramidal-ovoid, 6 × 2.4 mm.
Seeds

not carinate, 0.6–0.8 mm;

testa finely foveolate-reticulate.

Hypericum perforatum

Hypericum chapmanii
Phenology Flowering summer (Jun–Aug).
Habitat Pond margins, flatwoods, depressions
Elevation 0–10 m (0–0 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
FL
[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 chapmanii differs from H. fasciculatum in its taller, single-stemmed habit, thicker stems (to 10–15 cm diameter) with fluted, spongy bark containing large laticifers, and fewer-flowered inflorescences.

Hypericum chapmanii is known from the panhandle of northwestern Florida.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 6, p. 99. FNA vol. 6, p. 81.
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. 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. radfordiorum, H. scouleri, H. setosum, H. sphaerocarpum, H. suffruticosum, H. tenuifolium, H. tetrapetalum, H. virgatum, H. ×mitchellianum
Subordinate taxa
H. perforatum subsp. perforatum
Synonyms H. arborescens
Name authority Linnaeus: Sp. Pl. 2: 785. (1753) W. P. Adams: Contr. Gray Herb. 189: 22. (1962)
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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