Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Hypericum perforatum

Hypericum setosum

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

hairy St. Johnswort
Habit Herbs annual or perennial, erect, usually unbranched proximal to inflorescence, 2–8 dm.
Stems

internodes 4-lined, scabrous-tomentose to pilose.
Leaves

appressed to ascending, sessile;

blade narrowly ovate or lanceolate to narrowly oblong-elliptic (or proximal oblanceolate), 4–15 × 1.5–7 mm, subcoriaceous, margins recurved, apex acute to obtuse, surfaces scabrous-tomentose to pilose, basal veins 1(–5), midrib with 0–1 pair of branches.
Inflorescences

cylindric to subcorymbiform, to 30-flowered, branching mostly dichasial.
Flowers

5–11 mm diam.;

sepals ovate to ovate-lanceolate or obovate, subequal, 2.5–5 × 1.5–2.5 mm, margins setulose-ciliate, apex acute;

petals 5, deep yellow, obovate, 4–7 mm;

stamens (15–)20–40, filaments almost distinct;

styles 1.5–2 mm;

stigmas ± broadly capitate.
Capsules

ovoid to ellipsoid-subglobose, 3.5–5 × 2–3 mm.
Seeds

0.4–0.6 mm;

testa linear-reticulate.
2n

= 12.

Hypericum perforatum

Hypericum setosum
Phenology Flowering early–late summer (Jun–Sep).
Habitat Wet ditches, bogs, savannas, wet pinelands on sandy soil
Elevation 0–200 m (0–700 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
AL; FL; GA; LA; MS; NC; SC; TX; VA
[WildflowerSearch map]
[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 setosum is the only American Hypericum sp. with an indumentum. It is related to H. virgatum (H. denticulatum subsp. acutifolium); in addition to having the indumentum, it is generally smaller and less branched and has a different chromosome number.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 6, p. 99. FNA vol. 6, p. 91.
Parent taxa Hypericaceae > Hypericum > sect. Hypericum 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. 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. 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. sphaerocarpum, H. suffruticosum, H. tenuifolium, H. tetrapetalum, H. virgatum, H. ×mitchellianum
Subordinate taxa
H. perforatum subsp. perforatum
Synonyms Ascyrum villosum, Brathys tomentosa, H. pilosum, H. villosum
Name authority Linnaeus: Sp. Pl. 2: 785. (1753) Linnaeus: Sp. Pl. 2: 787. (1753)
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).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:
Northwest Wildflowers