Oligostema (Nomenclature)
Perennial or annual herbs up to 0.75 m tall, glabrous, very rarely with leaves glaucous beneath or undulate-papillose above, with stems erect to prostrate, radiating from taproot, unbranched below inflorescence or more usually branched at the base and sometimes from intermediate nodes, with dark (black) glands on stem, leaves, sepals, petals and anthers. Stem narrowly 2-lined to terete, eglandular or with glands on raised lines. Leaves opposite, decussate, sessile or subamplexicaul to shortly petiolate, free, persistent, chartaceous; lamina entire, with venation pinnate; laminar glands pale and/or black, punctiform or absent; intramarginal glands black; ventral glands absent. Inflorescence 1–c. 50-flowered, with branching dichasial to monochasial, without or rarely with one subsidiary branch. Flowers stellate, homostylous. Sepals 5(4), free or basally connate at the base, imbricate, persistent, erect in fruit, with margin fimbriate to entire; veins 3–5(–7); laminar glands pale and sometimes black, punctiform to linear; marginal glands black, intramarginal to sessile or on denticles to fimbriae, regular. Petals 5(4), persistent, erect but not twisting after flowering, without apiculus; margin entire or with prominent glands; laminar glands pale and sometimes black, striiform to punctiform; marginal glands black, often distal. Stamen fascicles ‘3’ (5), persistent, with stamens totalling c. 12–50; anther gland black; pollen type X. Ovary with 3(5) axile placentae, each ∞-ovulate; styles 3(5), diverging; stigma narrow. Capsule 3(5)-valved, subcoriaceous, with valves longitudinally narrowly vittate, the vittae sometimes interrupted or bearing small swellings. Seeds cylindric, not carinate or appendiculate; testa densely linear-foveolate.
BASIC CHROMOSOME NUMBER (X). 9, 8; ploidy 2.
Meadows , grazed pastures, rocky or stony or grassy slopes, waste ground, open woodland, on acidic to basic soils; 0–2000 m.
Mediterranean region, west and central Europe, northwest Africa, Macaronesia: British Isles, France, Spain, Portugal, Morocco, Algeria, Tunisia, Sardinia, Corsica, Menorca, Sicily, Italy, Crete, Cyprus; Israel (extinct); Serbia, Croatia, Slovenia, Hungary, Slovakia, Czech Republic, Austria, Switzerland, Germany, Belgium, Netherlands, Denmark, Sweden, Poland, Belarus, Ukraine, Romania, Madeira, Azores.
6 species.
In part 1 (Robson, 1977), I included H. aucheri Jaub. & Spach in Sect. Oligostema. Subsequent observation, however, has revealed that the anther glands in this species are amber, whereas in the rest of this section they are black. Hypericum aucheri has therefore been transferred to Sect. 16. Crossophyllum (now also including H. thasium, the sole member of Sect. 15. Thasia), in which the anther glands are nearly always amber.