Hypericum perforatum subsp. perforatum (Nomenclature)
Leaves usually petiolate; lamina (5-)12-25(-30) ´ (2-)5-10 mm, broadly to narrowly oblong or ovate to rarely elliptic or orbicular or obovate (l:b = (1-)2-3(-5)), base rounded to broadly cuneate, not glaucous beneath. Inflorescence not usually congested, with branches relatively short, straight. Petals with laminar glands all pale to mostly black. Capsule valves with lateral vittae linear, narrow or rarely swollen distally but not interrupted, the vesicles forming a regular row, not scattered irregularly.
2n = 32, 48 (see p. ).
Distribution of the species excluding (i) the Mediterranean region, Macaronesia, Jebel Marra, SW. Saudi Arabia (Asir), nearly all Asiatic Turkey, Transcaucasia and Iraq to NW. India; (ii) Kazakhstan and adjacent southern Russia; (iii) China. Introduced into North America, Mexico, Cuba, Haiti, Brazil (Paraná), Uruguay, Argentina, Chile, Juan Fernandez, Hawaiian Islands, New Zealand and Australia.
Subsp. perforatum typically has broad, relatively large leaves and large flowers and fruits with narrow linear oblique vittae. In dry habitats (e.g. chalk soils, walls), however, narrow-leaved smaller-flowered plants superficially resembling subsp. veronense are often seen; but these have lateral capsule vittae typical of subsp. perforatum or with the distal ends forming a line of vesicles, not irregular like those of Mediterranean forms of subsp. veronense. Such plants occur in England (and probably elsewhere in NW. Europe) as well as in the U.S.A. and Canada, the true subsp. veronense being absent from these areas. Where the distributions of subsp. perforatum and subsp. veronense overlap (in southern France, southern Germany, Austria and northern Italy), forms intermediate between the subspecies occur. These are similar to the northern dry-habitat forms in having narrow petiolate leaves, but the capsule glands are also intermediate in form, i.e. ± irregularly vesiculate but with several dorsal linear vittae. Examples of such intermediate specimens from Austria (Styria) were cited by Fröhlich (1911) as subsp. angustifolium, e.g. Fölling bei Maria Trost, 23 July 1910 (fr), Fröhlich GZU16326 (GZU). There is evidence that such populations show cytological irregularities (Garbari, in litt.)
It seems likely that subsp. perforatum was introduced into North America independently in the east and the west .
A low, erect to procumbent southern Balkan plant with small, rather broad leaves (l : b=1-2.5) and capsule valves bearing lines of vesicles has been named H. perforatum var. humile Stranski, but no valid description has been traced. On account of intermediate forms that link it with typical subsp. perforatum, it apparently belongs to that subspecies. Specimens have been seen from Albania, Bulgaria and Greece.
The 'type specimen' of H. assurgens Peterm. appears to be pure H. perforatum, not H. humifusum ´ perforatum as reported by Rouy & Foucaud; and the name does not appear on Petermann's Fl. Lips.: 563 (1838) as cited by them.
Hegi (1925: 528) reduced H. perforatum var. ellipticum Durand & Pittier to a form of var. vulgare.
Fröhlich also describes H. perforatum subsp. vulgare forma lineolatum (Jord.) A. Fröhl. in adnot. as "subvar. lineolatum", a later homonym of Rouy (1896).
Fröhlich (1911: 524) compares (synonymises?) H. perforatum var. alpinum Parl. with his forma lineolatum of subsp. vulgare.