Hypericum atomarium (Nomenclature)
Perennial herb 0.2-0.8 m tall, erect or decumbent but not rooting at base, with woody taproot, few-stemmed, unbranched below inflorescence or with short axillary shoots after fruit ripens, shortly whitish-pubescent on stems below inflorescence and on both leaf surfaces. Stems green, terete; internodes all shorter than leaves or upper (or more rarely all) exceeding them. Leaves sessile; lamina 15-45(-55) x 8-20(-22) mm, ovate to oblong or elliptic, paler beneath, thinly chartaceous, not glaucous, shortly pubescent beneath, usually shorter or puberulous above, plane, spreading; apex rounded, margin entire, base cordate-amplexicaul to rounded; venation: 3 pairs of laterals curved-ascending from lower 0.2-0.25 of midrib, tertiary reticulation dense, not or scarcely prominent; laminar glands all pale or sometimes scattered black ones distally and towards margin, dense to rather sparse, unequal; intramarginal glands black, dense to rather sparse. Inflorescence (12-)15-c. 200- flowered from (2-)5-8 nodes, without flowering branches from lower nodes, cylindric to rarely shortly and broadly rounded-pyramidal; pedicels 2-3 mm; bracts and bracteoles triangular-lanceolate to linear, black-glandular-ciliate, often with basal cilia somewhat longer but not auriculate. Flowers 15-20 mm in diam.; buds cylindric, rounded. Sepals 3.5-5 x 1-2.2 mm, subequal, free or almost so, narrowly oblong or oblong-lanceolate to elliptic or rarely lanceolate to ovate, obtuse (rarely acute) to rounded, with margin long-glandular-ciliate; veins 3, outer sometimes branched; laminar glands pale, striiform; marginal glands black, flat-topped. Petals pale yellow, not tinged red, (8-)9-12 x 3-3.5 mm, c. 2.5 x sepals, elliptic to oblanceolate, rounded, apiculus absent; laminar glands pale, punctiform to striiform, and also usually black, punctiform, scattered; marginal glands absent. Stamens 25-40, longest 6-8 mm, c. 0.65 x petals; anther gland black. Ovary 1.5-3 x 1-1.5 mm, ellipsoid; styles 3.5-5.5 mm, 1.9-2.3 x ovary, spreading-incurved. Capsule 5x3 mm, broadly ellipsoid, equalling or exceeding sepals, enclosed when developing by petals twisting together. Seeds dark reddish brown, 0.5-0.6 mm long; testa finely scalariform.
2n = 16 (Reynaud, 1973, 1980, 1981).
Stony places (schist or limestone) near streams or in damp shade; 30-1000 m.
Greece (E. Peloponnisos: Lakonia, Argolis; E. Aegean islands: Lesvos, Khios, Ikaria, Samos, Rhodos), Turkey (W. Anatolia from Bursa to Antalya). Naturalised in Portugal (cf. Ramos, 1993: 184).
H. atomarium is very closely related to H. annulatum subsp. annulatum, differing from it essentially in lacking proper auricles on the bracts and bracteoles and in having laminar black glands on the sepals, usually on the petals and sometimes on the leaves. This last character also distinguishes it from its sister species, H. lanuginosum, in which the sepals are usually more obtuse with shorter glandular cilia. H. atomarium and H. lanuginosum together form a south-eastern development from the Balkan H. annulatum, a population which split into a western and an eastern species. The laminar black gland character separates them well; although there are relatively few black glands on the sepals of the 'outlying' Antalya specimen cited above, they are numerous on the leaves. However, variability towards the western end of the distribution of H. lanuginosum (q.v.) may well indicate introgression from H. atomarium.
See H. cuisinii for a discussion of the relationships of that species to H. atomarium.
The other H. supinum Vis. syntype belongs to H. tomentosum L. var. β; see Robson (1967a: 196), where it was chosen as lectotype of H. supinum Vis.