Hypericum androsaemum
H. annulatum
H. calycinum
H. forrestii
H. 'Hidcote'
H. hircinum
H. hirsutum
H. humifusum
H. x inodorum
H. maculatum
H. montanum
H. olympicum
H. perforatum
H. pulchrum
H. tetrapterum
Hybrids
Key
References
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Hypericaceae

Taxa treated:
H. androsaemum
H. annulatum
H. calycinum
H. forrestii
H. 'Hidcote'
H. hircinum
H. hirsutum
H. humifusum
H. x inodorum
H. maculatum
H. montanum
H. olympicum
H. perforatum
H. pulchrum
H. tetrapterum
H. maculatum
x perforatum

H. maculatum
x tetrapterum
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 © Flora Nordica

by Lars Fröberg
(6a, 20070517)

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Hypericum L.     

Linnaeus, Sp. pl.: 785 (1753).
Literature. Hegi 1925, Robson 1985, 2002.
Hemicryptophytes or sometimes chamaephytes, rhizomatous or with decumbent to ascending stems from a tap-root; glands frequently present (dark or clear, stalked, sessile or immersed) in various combinations on stem, leaves, sepals, petals and anthers. Stem with or without wings/ridges decurrent from the nodes. Leaves opposite (rarely whorled), sessile to subsessile; blade ± rounded, with an entire margin. Inflorescence a thyrsoid or dichasium. Flowers usually 5-merous, with pale yellow to orange petals that are ± parallel-veined; stamens numerous, at the base combined in 3--5 fascicles or free; pistil single, superior, with 3--5 styles bearing one capitate stigma each. Fruit usually a 3-celled, many-seeded, septicidal capsule with raised vittae (oil channels) on the surface, rarely a berry.
Biology. The flowers are insect pollinated; the outer, shorter stamens open before the inner, longer ones. The seeds are small and mainly wind-spread (Hegi 1925).
Notes on diagnostic characters. The variation of secretory structures is great in the family, and of taxonomic importance, but not fully understood. Two types of internal glands,which are unique for the genus, occur (cf. Curtis & Lersten 1990). Clear glands (always immersed and laminal) are translucent, rounded to elongated or sometimes threadlike structures. Dark glands are ± opaque, rounded to elongated; they appear immersed or sessile (laminal or marginal) or stalked (always marginal).
The venation of the leaves and the vittae on the fruit surface are important diagnostic features for species 1-3, but not described for other species. Hold the plant up to the light to examine shape and size of clear glands and venation of leaves.
Hypericum pubescens Boiss. (F villakuisma), a pubescent herb with black glands on leaves and sepals, was reported from F U Helsinki 1940 (Moroccan cork; Pettersson 1951), but no material has been found. - H. perforatum x maculatum has been reported from Norden (Karlsson 1998), but all material proved to be either H. maculatum or H. perforatum. - H. maculatum x pulchrum was reported from N (Hylander 1955), but no material has been found. - H. maculatum subsp. obtusiusculum (F lännensärmäkuisma), an autotetraploid subspecies distributed in Central Europe (Robson 2002), has been reported from D (Karlsson 1998, Mossberg & Stenberg 2003) and F EP Vaasa (Hämet-Ahti 1998), but all specimens seen are H. maculatum ssp. maculatum.

1 Sepals ciliate with stipitate, black glands; internodes terete (rarely with 2 indistinct ridges not reaching the node below) 2
- Sepals without stipitate, black glands (sometimes a few in 7. H. humifusum); internodes with 2-4 ridges or wings, at least 2 of them reaching the node below 4
2 Stem and leaves densely hairy 5. H. hirsutum
- Neither stem nor leaves hairy (but leaves sometimes papillose beneath) 3
3 Leaves longer than 3 cm, with black glands along the margin 4. H. montanum
- Leaves shorter than 2 cm, without black glands along the margin 6. H. pulchrum
4 Plant low, decumbent, branched from the base; stem up to 1 mm thick 7. H. humifusum
- Plant medium sized, erect, without basal branches; stem thicker than 1 mm 5
5 Ridges on main stem winglike, at least some wider than 0.2 mm; clear glands in the leaves smaller than 0.1 mm; petals 5--8 mm long, usually without dark glands 3. H. tetrapterum
- Ridges on main stem not winglike, up to 0.2 mm wide; clear glands in leaves usually larger than 0.1 mm (but sometimes absent); petals longer than 8 mm, with several to many dark glands 6
6 Internodes with 2 ridges; sepals narrow, acute; petals with dark marginal glands at the apex 1. H. perforatum
- Internodes with 4 ridges (2 of them sometimes indistinct, not reaching the node below); sepals ovate to elliptic, obtuse to rounded; petals without marginal dark glands at the apex 2. H. maculatum

1. Hypericum perforatum L.   map     ill.

Linnaeus, Sp. pl.: 785 (1753). -- Type: Linnaean Herbarium 943.34 (LINN) [falsely printed “943.94”] lectotype, sel. by Robson, Fl. Iran. 49: 17 (1968).

D Prikbladet Perikon. F mäkikuisma. N prikkperikum. S äkta johannesört.

Hemicryptophyte. Erect, 30--85 cm, glabrous, with a (1.5--)3-7 mm thick rhizome. Stem 1.5-4.5 mm thick, distinctly brown-violet at the base, often distinctly glaucous; internodes on main stem 23-28(--31), the longest 2-6 cm, with 2 low but distinct ridges (decurrent from the midribs of the next leaf pair); lowest branch at node 6-13, lowest flowering branch at node 12-22(--26). Leaves 1.1-3.2 x (0.35--)0.5-1.6 cm, length/width ratio 1.6-3.3(--4.2), widest at the middle (40-60% from base), thick, usually paler beneath; tertiary veins indistinct; base rounded to broadly attenuate; apex broadly to narrowly obtuse; margin usually recurved or revolute; dark glands few to rather many, mainly submarginal (in the distal third sometimes also laminal); clear glands rather few to many, usually larger than 0.1 mm.
Inflorescence raceme- to corymb-like, 1-3 times (usually twice) branched, branches to 3-21 cm. Flowers always 5-merous; buds obtuse to subacute, narrowly ovate in outline. Sepals 4.5-7 x 1-2.5 mm, narrowly triangular to lanceolate, equal in size; apex acute to acuminate; veins 3-5, distinct; glands laminal only, few to many, often elongated (clear ones frequently vein-like, dark ones sometimes absent). Petals (7--)10-16 x (2--)4-6 mm; clear glands and marginal dark glands usually present (several dark ones in upper part, vein-like clear ones all over), sometimes also some elongated laminal dark ones;most of the veins united towards the apex. Stamens with up to 7-12 mm long filaments; anthers 0.4-0.6 mm, with a dark gland at one end. Fruit 5.5-8.5 x 3-6.5 mm (length/width ratio 1.3-2), dark brown or dark greenish-brown; vittae fairly thick, the peripheral ones of each carpel short, converging; styles 3-5.5 mm; pedicel 1-4 mm. Seeds 0.9-1.1 x 0.4-0.5 mm, subcylindrical, grey or brownish grey to black; surface reticulate. - Mid-summer to late summer.
2n=32 + 0-2B (S Sk).
Distribution. [Nem-SBor(--MBor)] - Indigenous in the south, anthropochorous in the north. D common throughout. N common in the southeast, north to central Op; scattered to rare along the fjords and in the lowland valleys, rarer at the very coast, north to SNo Lurøy; Tr Målselv 1948 (weed). S common to fairly common north to central Vrm and southeastern Dlr, scattered to rare in the lowland further north to southern Ång; casual further north along the coast (partly brought in with ballast). F common as indigenous in the archipelago of A and V, elsewhere scattered (mainly on rock outcrops, especially on open, south-facing slopes) in coastal areas east to EK and north to southern and eastern St, inland to northern EH and ES; also anthropochorous in the inland and further north (brought in especially with railway traffic).
Europe, N Africa, SW Asia and C Siberia; introduced in Australia, North and South America.
Habitat. Usually sun-exposed on mostly dry, often sandy soil; pavement, dry grassland, eskers, fringes and open woodland; also in man-made sites such as roadsides, railway banks, gravel-pits and other ruderal ground. Probably favoured by lime.
Variation. Hypericum perforatum is quite variable in, e.g., habit, leaf-shape and shape of sepals. It is an allotetraploid species, apparently derived from hybridization between H. attenuatum Fisch. ex Choisy and H. maculatum (Robson 2002). H. perforatum is an apomictic species with a pseudogamic type of reproduction, i.e. that pollination occurs but new individuals are predominantly produced from unreduced egg cells. Hybridization may occur with the diploid species H. maculatum and H. tetrapterum, but is rare. The offspring is either triploid (when a reduced egg cell of the diploid species is fertilized by a reduced male gamete of H. perforatum) or pentaploid (when an unreduced egg cell of H. perforatum is fertilized by a reduced male gamete of the diploid species); triploid hybrids will presumably be ± intermediate between the parents, while pentaploid ones will be more similar to H. perforatum (Robson 2002). Only one record of a hybrid between H. perforatum and H. tetrapterum has been identified on morphological basis in the material from Norden; no record of H. maculatum x perforatum has been confirmed. Some specimens that morphologically correspond to H. perforatum have reduced pollen fertility, and may be suspected to be pentaploid hybrids; however, a reduction of pollen fertility occurs frequently in H. perforatum due to meiotic abnormalities (Robson 2002), and such specimens have therefore provisionally been referred to H. perforatum.
Similar taxa. See H. maculatum (2) and H. humifusum (7).

2. Hypericum maculatum Crantz   map     ill.

Crantz, Stirp. Austr. 2: 64 (1763). -- Type: Austria “Alpen” 1760, Crantz 828 (BP) lectotype, sel. by Robson, Bull. Mus. Nat. Hist. 32: 68 (2002).
H. qudrangulum auct., non L.

D Kantet Perikon. F särmäkuisma. N firkantperikum. S fyrkantig johannesört.

Hemicryptophyte. Erect, 35--75 cm, glabrous; rhizome 1.5--4 mm thick. Stem 1.5-3.5 mm thick, distinctly brown-violet at the base, not glaucous; internodes on main stem 16--24 (the longest (2.5--)3.5-6 cm), with 4 low ridges (2 distinct ones decurrent from the midribs of the leaves, and 2 rather distinct ones decurrent from the interspaces between the leaf insertions); lowest branch at node 3-15, lowest flowering branch at node (7--)10-19. Leaves (2-)2.4-4.5 x 1-2.4 cm, length/width ratio 1.5-2.8, widest just below the middle (30-50% from base), thin, slightly paler beneath; tertiary veins forming a distinct network; base shallowly cordate to broadly attenuate; apex rounded or sometimes truncate; margin flat; dark glands rather many, mainly submarginal (rarely also laminal); clear glands few to many (sometimes absent), usually larger than 0.1 mm.
Inflorescence raceme- to corymb-like, 1-3 times (usually twice) branched, with up to 2-15 cm long branches. Flowers 5-merous (rarely also 4-merous ones present); buds rounded to obtuse at apex, oblong in outline. Sepals 3.5-6 x 2--3 mm, ovate or elliptical, unequal in size; apex obtuse to rounded; veins 5-7, distinct; glands all laminal, mostly ± rounded, few to many, usually both dark and clear ones (sometimes only dark ones present). Petals 9--13 x 4-6(--7) mm; dark glands rather many, all laminal, some often elongated or vein-like; clear glands absent or few; most of the veins united towards the apex. Stamens with up to 6--11 mm long filaments; anthers 0.4-0.7 mm, with a dark gland at one end. Fruit 5.5-8 x 4-6 mm (length/width ratio 1.3-1.8), dark violet-brown or greenish-brown; vittae fairly thin, all similar, ± parallel; styles 2-4 mm; pedicel 1-7 mm. Seeds 0.7-0.8 x 0.3-0.35 mm, subcylindrical, light grey-brown to grey-brown; surface reticulate. - Mid-summer to late summer.
2n=16 (S Sk).
Distribution. [Nem-NBor] - Indigenous in the south, in the north a rather recent incomer. D common throughout. N common in the southeast, north to central He and Op, and along the very coast and fjords and in the lowland valleys, north to southern SNo; scattered further north to southern NNo and the Lofoten area, Tr Harstad; casual in VFi Alta and ØFi Sørvaranger (both with German troops). S common to rather common north to central Dlr, the whole of Hls and Mpd, and central coastal Ång; further north scattered to rare as a recent incomer in the lowlands and up to the subalpine region in the southern mountains. F common north to southern EP, and central parts of PH, PS and PK; scattered north to central Kn, in the southern boreal zone mostly ± clearly archaeophytic; north of Kn a rare recent incomer, mostly brought in during World War II. Fa Streymoy and Vágar, perhaps introduced (Fosaa 2000).
Europe except the extreme north and parts of the Mediterranean.
Habitat. On moist to dry soil in sun-exposed to slightly shaded places; glades and fringes of deciduous woodland, overgrown pasture and damp grassland (earlier also mown grassland); also in man-made sites such as roadsides, ditches, clearings and former fields.
Similar taxa. Hypericum maculatum is similar to Hypericum perforatum (1). H. maculatum differs, in addition to key characters, by fewer (15-23) internodes, stems and leaves that are not glaucous, proportionally wider and thinner leaves that are flat and have a more distinct network of tertiary veins, buds that are more rounded, shorter styles (2-4 mm long), and fruits with narrow vittae which are all longitudinal.

3. Hypericum tetrapterum E. Fries   map     ill.

Fries, Nov. Fl. Suec.: 94 (1823). -- Type: S Sk “in silva Refsten” 1819 (?), E. Fries s.n. (UPS) holotype.
H. quadrangulum L. (1753), nom. rej. -- H. acutum Moench, Meth.: 128 (1794), nom. illeg.

D Vinget Perikon. F ojakuisma. N vingeperikum. S kärrjohannesört.

Hemicryptophyte. Erect, 35--70 cm, glabrous; rhizome 1.5-4.5(--6) mm thick. Stem 1.5-3 mm thick, distinctly brown-violet at the base, not or slightly glaucous; internodes on main stem 12-21 (the longest 3--8 cm), quadrangular with a distinct ridge (wing) on each angle (the two wings decurrent from the interspaces between the leaf insertions sometimes slightly narrower); lowest branch at node 5-11(--13), lowest flowering branch at node 8--18. Leaves 2.2-3.5 x (1--)1.3-2.4 cm, length/width ratio 1.3-2.1(--2.4), widest just below the middle (usually 40--50% from base), thin, usually slightly paler beneath; tertiary veins forming a distinct network; base rounded to slightly cordate; apex usually broadly obtuse to rounded; margin flat; dark glands few to rather many, mainly marginal (in the distal third also laminal); clear glands very many, smaller than 0.1 mm.
Inflorescence usually corymb-like, 3--5 times branched, with up to 4--16 cm long branches. Flowers always 5-merous; buds obtuse to acute, ovate to elliptic in outline. Sepals 3.5--6 x 1-1.5(--2.5) mm, lanceolate; apex acute; veins 3-5(--7), distinct; clear glands present (few to many, often elongated); dark glands absent or a few ± marginal ones in upper part. Petals 5-7(--7.5) x 2--3 mm; most of the veins united towards the apex; clear glands few, elongated to veinlike; dark marginal glands sometimes present in the upper part. Stamens with up to 4--6 mm long filaments; anthers 0.4-0.5 mm, with a dark gland at one end. Fruit 6-7(--8) x 3-4(--5) mm, length/width ratio 1.6-2(--2.2), dark brown or dark greenish-brown; vittae fairly thin, all similar, ± parallel; styles 1.5-2 mm; pedicel 1--3 mm. Seeds 0.7-0.8 x 0.3-0.4 mm, subcylindrical, light to dark brown; surface reticulate. - Late summer.
2n=16 (S Sk).
Distribution. [Nem] - Indigenous in D and S Sk; a newcomer further north. D rather common to scattered in the islands and southeastern Jylland, scattered to fairly rare in the northern and western oligotrophic parts of Jylland. S Sk scattered mainly in eutrophic areas; BhG Göteborg 1927 (Gullbergsgärde) and 1937 (Backa), Mölndal 1944, and Vg Lerum 1996 (swamp woodland).
C and S Europe, N Africa, SW Asia; introduced in New Zeeland.
Habitat. On moist to wet soil in sunexposed or slightly shaded wetlands; overgrown meadows, borders of calcareous fens, brooks, springs, eutrophic lake shores and open swamp woodlands. Favoured by lime.

4. Hypericum montanum L.   map

Linnaeus, Fl. Suec. ed. 2: 266 (1755). -- Type: Linnaean Herbarium 943.39 (LINN) lectotype, sel. by Robson, Bull. Brit Mus (Nat. Hist.) Bot. 26: 196 (1996).

D Bjerg-Perikon. F vuorikuisma. N bergperikum. S bergjohannesört.

Hemicryptophyte. Erect, 40--80 cm, not branched below the inflorescence, slightly caespitose, mostly glabrous; rhizome 1.2-4(--7) mm thick. Stem 2-3(--4) mm thick, distinctly brown-violet at the base, glabrous or rarely papillose beneath the leaf insertions, usually distinctly glaucous; internodes on main stem 14--25 (the longest 5--12 cm), terete or rarely with 2 indistinct ridges just below the leaf insertions; lowest flowering branch at node 11-18(--22). Leaves 3.7-6.4(--6.9) x 1.4-2.8(--3.3) cm, length/width ratio 1.9-2.6, widest below the middle (30-40% from base), distinctly paler and papillose beneath; base cordate to rounded; apex broadly to narrowly obtuse; margin flat; dark glands many, marginal (in the distal third also laminal); clear glands many but sometimes indistinct.
Inflorescence raceme-, corymb- or head-like, with crowded flowers, 1-3 times (usually twice) branched, with up to 1-4(--7) cm long branches. Flowers always 5-merous. Sepals 5--7 x 1.5--3 mm, usually lanceolate; apex acute; veins 3-5, distinct; dark glands stalked, along the whole margin; clear glands elongated and vein-like. Petals 9.5--13 x 3-4.5(--5.5) mm, without glands; veins all separate, or sometimes a few united towards the apex. Stamens with up to 7-9 mm long filaments; anthers 0.4-0.6 mm, with a dark gland at one end. Fruit 5.5-8 x 3.5-5.5 mm, length/width ratio 1.2-1.8, usually dark reddish-brown, styles 2.5--4 mm; pedicel 1-3 mm. Seeds 0.7-0.9 x 0.3-0.4 mm, subcylindrical, yellow-grey or brownish grey to almost black; surface reticulate. - Mid-summer to late summer.
Distribution. [Nem-BNem] - scattered in Brn, northern Sjæ, northern Jylland south of Limfjorden and southeastern Jylland, elsewhere rare; declining throughout. N fairly rare in the lowland, along the fjords and at the very coast from Øf to northern SF (but absent in southern Ro). S scattered to fairly rare, and declining, in the southern lowlands north to southwestern Vrm, northern Vg, central Ög and northeastern Srm (but rare in southwestern Sk and in Öl, and possibly absent from southern Klm). F V Lohja (cliff terraces and roadsides in calcareous pine forest, seven small stands within c. 1 km2, known since 1888).
W and C Europe, N Africa and SW Asia.
Habitat. Dry, sunexposed to slightly shaded sites; on thin soil or in rock crevices in thin grassland, scrub or open deciduous woodland, often on or above a steep slope; road cuttings. A poor competitor favoured by surface disturbances, and more or less limited to basic rock.
Variation. The density of the inflorescence varies in H. montanum; most morphotypes have a dense, head-like inflorescence, but some have a ± lax raceme- or corymb-like one instead. One of these latter morphotypes has been described (from S, northern Hl) as genetically distinct (Nilsson 1966).

5. Hypericum hirsutum L.   map

Linnaeus, Sp. pl.: 786 (1753). -- Type: Linnaean Herbarium 943.41 (LINN) lectotype, sel. by Robson, Fl. Iran. 49: 15 (1968).

D Lådden Perikon. F karvakuisma. N lodneperikum. S luden johannesört.

Hemicryptophyte. Erect, 40--100 cm, slightly caespitose, hairy; rhizome 2--4 mm thick. Stem 2-3.5 mm thick, usually brown-violet at the base, usually not glaucous; internodes on main stem 21-30 (the longest 3.5--7 cm), terete or sometimes with 2 indistinct ridges just below the leaf insertions; the lowest branch at node 8--16, the lowest flowering branch at node 15--23. Leaves 3.3-6.2 x (1.1--)1.4-2.7 cm, length/width ratio 1.6-2.8(--3.4), widest just below the middle (40-50% from base), sparsely hairy on the upper side, densely hairy and usually beneath; base broadly cuneate to rounded; apex obtuse to retuse; margin flat; clear glandsfrequent (no dark glands).
Inflorescence usually raceme-like, 2-3 times branched, with up to 1-8(--23) cm long branches. Flowers always 5-merous. Sepals 3.5--5 x 1--2 mm, lanceolate; apex acute; veins 3-5, distinct; dark glands stalked, along the whole margin; clear glands elongated and vein-like. Petals 8-11(--12.5) x 2.5-4.5 mm, with a few dark stalked glands at apex and several indistinct, ± elongated and vein-like clear ones; most of the veins united towards the apex. Stamens with up to 6--9 mm long filaments; anthers 0.4-0.5 mm, with a clear gland. Fruit 5-7(--8) x 3-4 mm, length/width ratio 1.4-1.8, dark brown or dark greenish-brown; styles 3-5 mm; pedicel 1-3 mm. Seeds 0.9-1.1(--1.3) x 0.3-0.45 mm, subcylindrical, reddish brown to dark reddish brown; surface papillose. - Mid-summer.
Distribution. [Nem-MBor] - D fairly common in LFM, southern FyL and northeastern Brn, scattered in other parts of the islands, and in eastern Jylland north to Randers fjord. N fairly rare at Oslofjorden, in central Op and He Ringsaker; scattered to fairly rare along the fjords and in the lowland valleys from Ho Eidsfjord to northern NNo (from ST to NNo more common, occurring also on the very coast). S scattered to fairly rare in the lowlands of Sk, Öl except the southeastern parts, BhG on the islands in the northern parts and around Marstrand, Ög and Vg (mainly in the calcareous areas), eastern Srm, southern and central Upl and southeasternmost Vsm. F scattered in the archipelago of A and V; possibly native also in V Lohja 1937 (mixed forest); other records (U Nurmijärvi 1993 and EH Tampere) probably originating from cultivation.
Europe except the northeastern parts and the Mediterranean; also Caucasus and C Siberia.

Habitat. On moist to fairly dry, often clayey soil in slightly to rather shaded places; open deciduous woodland, scrub, overgrowing pasture, fringes and roadsides. Favoured by lime.

6. Hypericum pulchrum L.   map

Linnaeus, Sp. pl.: 786 (1753). -- Type: Bauhin & Cherler (1651, fig. p. 383; epitype in BM) lectotype, sel. by Robson, Nord. J. Bot. 22: 81 (2002).

D Smuk Perikon. F nummikuisma. N fagerperikum. S hedjohannesört.

Hemicryptophyte or chamaephyte. Ascending to erect, often richly branched at the base, 30--45 cm, glabrous. Stem 1--2 mm thick, at the base usually distinctly brown-violet, usually distinctly glaucous; internodes on main stem (12--)16-22 (the longest 3.5-6.5 cm), terete (or sometimes with 2 indistinct ridges just below the leaf insertions); lowest branch at node 5-12(--14), lowest flowering branch at node 8-18. Leaves 1.1-1.6 x 0.8-1.2 cm, length/width ratio (1.2--)1.4-1.9, widest near the base (usually 20-40% from base), distinctly paler beneath; base cordate to rounded; apex broadly obtuse or rarely truncate; margin ± translucent, usually flat; clear glands frequent (no dark glands).
Inflorescence raceme-like, 1-2 times branched, with up to 2--8 cm long branches. Flowers always 5-merous. Sepals 2.5--4 x 1.5-2.5 mm, broadly elliptic to obovate; apex obtuse; veins 3-7, distinct; dark glands stalked, along the margin except at the base; clear glands frequently elongated and vein-like. Petals 7.5--10 x 3-4.5 mm; veins not united towards the apex; dark glands stalked, along the margin except at the base; clear glands indistinct, ± elongated and vein-like. Stamens with up to 6--8 mm long filaments; anthers 0.4-0.5 mm, with a clear gland. Fruit 5--7 x 3.5--4.5 mm, length/width ratio 1.4-1.7, dark brown or dark greenish-brown; styles 3-3.5 mm; pedicel 1-2 mm. Seeds 0.9-1.2 x 0.35--0.45 mm, subcylindrical, light grey-brown to grey-brown; surface reticulate. - Mid-summer.
Distribution. [Nem-BNem]. Oceanic.- Indigenous in heath vegetation, declining in some areas; rarely a newcomer with timber. D scattered to fairly common in Jylland, elsewhere declining and now only in western Fyn, northeastern Sjæ and Brn; previously also in southwestern Sjæ (latest c. 1910) and LFM Møn (Store Klinteskov, latest c. 1945). N fairly common along the very coast and fjords from AA Risør to NT Leksvik; Bu Hurum (brought in with timber). S regarded as indigenous in the southwest: Sk (one record, Brösarp 1889-91, stone fence), Hl Varberg 1907, Tölö/Kungsbacka and Släp both 1810’s, Ölmevalla (known since 1959), BhG Göteborg area (3 localities), locally common between Hjärtum and Solberga, Tossene (recent find in open heath woodland); casual in Bl Hjortsberga 1947 (mixed needle woodland), Klm Döderhult at least1985-97 (with timber from NW Germany, probably introduced in the 1970’s). Fa common.
W Europe.
Habitat. On dry, often sandy soil in sunexposed places; dry heathland, besides pavements, open heath woodland and on cliffs; calcifuge.

7. Hypericum humifusum L.   map

Linnaeus, Sp. pl.: 785 (1753). -- Type: Linnaean Herbarium 943.35 (LINN) lectotype, sel. by Robson, Nord. J. Bot. 22: 81 (2002).

D Dværg-Perikon. F matalakuisma. N dvergperikum. S dvärgjohannesört.

Hemicryptophyte or chamaephyte. Decumbent, richly branched at the base, with (3--)9--20 cm long shoots, glabrous. Stem 0.5--1 mm thick, distinctly brown-violet at the base, not to slightly glaucous; internodes on main stem 14-23(--27), the longest 0.9-1.8(--3.3) cm, with 2 distinct ridges, decurrent from the leaf pair above; lowest branch (apart from basal ones), which is usually also the lowest flowering branch, at node 11--23. Leaves 0.9-1.4(--1.8) x 0.3-0.5 cm, length/width ratio 2-4.8, widest at the middle (40-60(--70)% from base), usually slightly paler beneath; base usually cuneate; apex broadly to narrowly obtuse, or sometimes truncate; margin sometimes revolute; glands few (both dark and clear, the dark ones marginal).
Inflorescence corymb-like, 2-3 times branched, with up to 2--7 cm long branches. Flowers always 5-merous. Sepals 3.5--6 x 1.5-2.5 mm, lanceolate to elliptic; apex acute or obtuse; veins 3-5, distinct; glands absent or present (often dark sessile glands along the margin, sometimes also a few stalked dark ones at apex and a few clear elongated, vein-like ones). Petals 4-6.5 x 1.5-2.5 mm; veins all separate, or sometimes a few united towards the apex; dark glands stalked, few, along the margin except at the base; clear glands usually present but indistinct, ± elongated and vein-like. Stamens with up to 3-4(--5) mm long filaments; anthers 0.3-0.4 mm, with a clear to brownish gland at one end. Fruit 3.5--6 x 2.5-3.5 mm, length/width ratio 1.4-1.8, dark brown or dark greenish-brown; styles 1.5--2 mm; pedicel 1.5--7 mm. Seeds 0.5-0.7 x 0.3-0.4 mm, subcylindrical, grey-brown to black-brown; surface reticulate. - Early summer to late summer.
2n=16 (S Sk).
Distribution. [Nem-BNem] - Indigenous in the south. D fairly common to scattered in most of the country, rare in western Jylland and Brn. N AA Grimstad 1937 (nursery). S Sk scattered to rare in oligotrophic areas (mainly in the south), rare in southeastern Bl (recent finds in Ramdala and Sturkö), Klm several localities along the coast between Kalmar and Västervik, also inland (e.g. Algutsboda and Tveta); Öl Borgholm 1901, Hl Laholm 1980 (nursery), Veinge 1980’s (garden), Enslöv 1945 and Breared 1990 (both gravelly roadsides), Lindome 1952 (field), BhG Askim 1963 (weed), Tossene 1984 (south-exposed pasture), Resteröd and Forshälla, Vg Torsö 1994, 1997 (former field). F U Helsinki 1940 (with Moroccan cork).
W and C Europe, N Africa; introduced in S Africa and New Zeeland.
Habitat. On dry to moist, often exposed soil in sun-exposed places; heathland, open heath woodland, abandonded fields, besides pavements, former railways and along paths; calcifuge.
Similar taxa. Practically all shoots of Hypericum humifusum bear flowers. Non-flowering, weak, trailing basal shoots of H. perforatum (1) will key out as H. humifusum, and are sometimes mistaken for that species, but H. perforatum has thicker leaves.

Rare casuals

Hypericum androsaemum L. 1753. - Low shrub. Stem with 2 ± distinct ridges. Leaves not coriaceous, narrowly ovate to elliptical, with an apiculate to truncate apex; blade distinctly paler beneath, densely net-veined, but with less distinct veins than in H. calycinum; clear glands very frequent but indistinct (no dark glands). Flowers rather small, with petals and stamens shorter than the 8-12 mm long sepals; styles 3, 2-3 mm, shorter than the ovary. Fruit a dark berry, with the sepals persisting at fruiting stage.
Grown for ornament and probably also as a medicinal plant. D ØJy Juelsminde 2003 (path in woodland), FyL Tranekær 1998 (young woodland with ash, will apparently become established), Sjæ Ørholm (Ravneholm skov) 1989. - W Europe, the Mediterranean and SW Asia. - Map (not in the book).
Hypericum annulatum Moris 1827. - Medium-sized, perennial herb. Stem terete, with short hairs (glabrous in upper part). Leaves hairy on both sides, with dark and clear glands (dark ones submarginal). Flowers rather small; bracts and sepals have stalked dark glands along the margin, and the bracts have auricles that are densely covered with similar glands.
D Sjæ København 2000 (former railway). - The Balkan peninsula and Sardinia (subsp. annulatum); E Africa (other subspecies). - Map (not in the book).
Hypericum calycinum L. 1767. F turkinpensaskuisma. N krypperikum. S prakthyperikum. - Low shrub. Stem with 4 distinct ridges. Leaves leathery, elliptical (widest at or just beneath the middle), with a rounded apex, slightly paler and prominently net-veined beneath; clear glands very frequent but indistinct (dark glands absent). Flowers rather large, with rounded sepals; stamens of about the same length as the petals; anthers red-violet, c. 1 mm; styles 5.
Grown for ornament. D Brn Svaneke 1937 (woodland), FyL Otterup 2001 (filling earth), Odense 1995. S Bl Ronneby 2002 (refuse tip), Öl Köping 1999 (garden relic). - Bulgaria and Turkey. - Map (not in the book).
Hypericum ‘Hidcote’ (probably H. xcyathiflorum N. Robson x calycinum L.). S vinterhyperikum. - Lit.: Robson 1985. - Shrub with ± terete stem. Leaves leathery, narrowly ovate (widest near the base), with a rounded to apiculate apex, similar to those of H. calycinum but lower side distinctly paler and loosely net-veined. Flowers rather large, with rounded sepals; stamens about half the length of the petals; anthers yellow, 1.5-2 mm; styles 5, as long as the ovary or slightly longer (in H. calycinum much longer than the ovary).
Grown for ornament; escaped in D ØJy Them 2000 (outside plantation) and S Klm Västervik 2003 (refuse tip). - Probably originated in cultivation.
H. forrestii (Chitt.) N. Robson, S buskhyperikum, is cultivated in Norden and may be expected as an escape; it is similar but differs in, e.g., having orange anthers and styles that are shorter than the ovary. H. forrestii was reported from Norden by Karlsson (1998) but only one specimen has been found (D SJy Als, probably planted in the site); all other specimens examined proved to be the cultivar ‘Hidcote’. - A report from the refuse tip at S Klm Västervik 1997 could not be confirmed (specimen disappeared). - Map (not in the book).
Hypericum hircinum L. 1753. - Similar to H. androsaemum, but larger. Leaves with a scent of goats. Flowers with 2-3 mm long sepals and 12-16 mm long petals; styles c. 15 mm long, at least 3 times as long as the ovary. Fruit a capsule; sepals not persisting at fruiting stage.
Grown for ornament.D NJy Svankær 1951 (garden relic). - The Mediterranean and SW Asia. - Map (not in the book).
Hypericum x inodorum Mill. 1768 (H. androsaemum x hircinum). F marjakuisma. - Similar to H. androsaemum, but larger. Flowers with 12-16 mm long petals and 4-7 mm long sepals; styles 8-9 mm long, 1.5-2 times as long as the ovary. Fruit a capsule; sepals persisting at fruiting stage.
Grown for ornament; escaped in D Sjæ Helsingør 1995 (beech forest, probably throwout), Søllerød 1996 (escaped in woodland). [S Sk Malmö 1910 (possibly from cultivation).] - Probably of garden origin; possibly spontaneous in NW Mediterranean. - Map (not in the book).
Hypericum olympicum L. 1753. S olympjohannesört. - Low, procumbent to ascending herb, richly branched at the base. Stem and leaves glabrous, the latter small with translucent glands and few submarginal dark glands. Flowers ± solitary, wider than 2 cm across; sepals broad, overlapping, without glands; petals almost without glands.
S Klm Kläckeberga 1995 (roadside). - The Balkan peninsula and Turkey. - Map (not in the book).

Hybrids

All known material reported as Hypericum maculatum x perforatum (H. x desetangsii Lamotte), F ristikuisma) has been redetermined to either parent; see above under H. perforatum (1).
Hypericum perforatum x tetrapterum (H. x medium Peterm.). - Stem slightly glaucous, with 2 distinct ridges. Leaves fairly thick, with small and large translucent glands intermingled. Inflorescence richly branched. Flowers intermediate in size.
D FyL Hindsholm 1961 (roadside). - Pollen fertility is not reduced, but the specimen is morphologically intermediate between the parents. - See further under variation of H. perforatum. - Map (not in the book).
Hypericum maculatum x tetrapterum (H. x laschii A. Fröhl.) - Stem with 2 narrow and 2 broad ridges. Leaves usually with small and large clear glands intermingled. Inflorescence as in H. tetrapterum, but often rich in flowers; sepals 3.5-5 x 1.5-2.5 mm, ± ovate, acute to obtuse; petals 7-9 x 3-4 mm, with few dark glands; filaments 5-7 mm.
D Brn Rønne 1896, Bagaa 1913, Sjæ Søndersøen 1889, Åstrup skov 1973, FyL Svendborg 1866, 1872, SJy Toftlund 1965, VJy Resen (Ørgård) 1965, ØJy Horsens 1888. S Sk scattered within the distribution area of H. tetrapterum. - A record from S Mpd Timrå 1902 was based on a probably mislabelled collection. - Map (not in the book).

References To top

Curtis, J.D. & Lersten, N.R. 1990: Internal secretory structures in Hypericum (Clusiaceae): H. perforatum L. and H. balearicum L. New Phytol. 114: 571-580.

Fosaa, A.M. 2000: Wildflowers in the Faroe Islands - checklist. Føroya Nátturugripasavn.

Hämet-Ahti, L., Suominen, J., Ulvinen, T., Uotila, P. & Vuokko, S. 1998: Retkeilykasvio [Field flora of Finland], ed.4. Helsinki.

Hegi, G. 1925: Hypericaceae. In G. Hegi, Illustrierte Flora von Mitteleuropa 5(1): 498-534. München.

Hylander, N. 1955: Förteckning över Nordens växter, 1 kärlväxter. Lund.

Karlsson, T. 1998: Förteckning över svenska kärlväxter. Svensk Bot. Tidskr. 91: 241-560.

Kurtto, A. & Lahti, T. 1987: Suomen putkilokasvien luettelo. Checklist of the vascular plants of Finland. Pamphlet Bot. Museum Univ. Helsinki 11.

Mossberg, B. & Stenberg, L. 2003: Den nya nordiska floran. Wahlström & Widstrand. Stockholm.

Nilsson, Ö. 1966: Tillägg till floran i Fjärås socken. Svensk Bot. Tidskr. 60: 293-309.

Pettersson, B. 1951: An alien flora on Drumsö (Helsingfors) introduced by cork bark imported from Morocco and Spain. Mem. Soc. pro Fauna & Flora Fennica 27: 111-117.

Robson, N.K.B. 1985: Studies in the genus Hypericum L. 3. Bull. Brit. Mus. (Nat. Hist.) Botany 12: 163-325.

Robson, N.K.B. 2002: Studies in the genus Hypericum L. 4(2). Bull. Brit. Mus. (Nat. Hist.) Botany 32: 61-123.

notes