English: Mount Olympus St. John's wort
Region: Southeastern Serbia, Macedonia, Albania, Bulgaria, Greece, northwestern Turkey; introduced to England
invasive in Belgium and France.
Habitat: sandy, stony, sometimes grassy places; among rocks in open ground, in pine woodland; elevations of 0–2000 m; in chalk, clay, sand, loam soil; requires moist ground, but with sharp drainage.
Content: acylphloroglucinol, olympicin; amentoflavone, antidepressant; flavinoids, tannins, antioxidizing; hypericin, pseudohypericin
Use: ornamental with large, showy flowers, far larger than other Hypericums.
Culture: toxic to dogs, cats, horses.
BotanyShrub or subshrub; 0.1–0.55 metres tall; decumbent, or rarely prostrate.
Stem: few to numerous, caespitose, occasionally rooting, unbranched below its flowers; internodes are 5–15 millimetres long, short or longer than the leaves.
Leaves: spreading to erect; ± glaucous; 5–30 by 2–12 millimetres in size; elliptic or rarely lanceolate-elliptic, concolorous, thinly coriaceous; apex is acute to subacute or rounded-obtuse, with a rounded or cuneate base; 0-3 pairs of lateral veins; unbranched; laminar glands are pale and not prominent; intramarginal glands are black, small, and few in number.
Inflorescence: 1–5 flowered, up to nine; grow from three nodes.
Flowers: large, showy, relative hardy; dense shape; flower from June to August; pedicels are 2–4 millimetres long, rather stout; bracts reduced-foliar, broadly imbricate, lack black glands; bracteoles similar but smaller in size; 30–65 millimetres; buds are ovoid-pyramidal, rounded.
Calyx: sepals unequal or subequal, broadly imbricate, paler than the leaves; 6–16 by 3–12 millimetres, broadly ovate to lanceolate, with rounded base, entire, large, pointed, persistent in fruit, with 9–15 veins that are branching; laminar glands are pale and linear, a few can be black and punctiform; marginal glands absent, rarely one or two black apical ones.
Corolla: petals golden or pale yellow, tinge or lines of red.; 15–30 by 8–12 millimetres; twice as many as sepals; rounded; apiculus is short, acute to obtuse; laminar glands are pale and linear; their marginal glands are absent or black, 1 to 7.
Stamens: around 65–125 stamens; 14–25 millimetres long.
Ovaries: 3 by 2.5 millimetres; broadly ovoid; styles 18–23 millimetres; six to eight times as many as the ovaries.
Seed: capsule; 5–10 by 4–8 millimetres and is shorter than the sepals; broadly oval-like to spherical; dark brown.
TaxonomyHypericum olympicum is very similar to Hypericum polyphyllum
BotanyAction: antibacterial; antioxidant; antidepressant.