Perennial herb. Stems 10-110 cm long, erect, or sometimes rooting at the base, 2-lined, smooth, with branches ascending. Leaves sessile or subsessile, 5-35 mm long, 2-14 mm broad, narrowly ovate to elliptic-oblong or linear or sometimes oblanceolate, apex obtuse or mucronate to rounded, base cuneate to rounded, entire with intramarginal and often a few laminar black glands. Inflorescence a (1-)5-many-flowered, subcorymbose or broadly pyramidal cyme with ultimately monochasial branches; flowers 1.5-2.5 cm in diameter. Sepals 3-6 mm long, lanceolate to oblong or elliptic, acute to acuminate or shortly aristate, free, entire.. Petals + narrowly oblanceolate, 8-15 mm long, with marginal black dots and sometimes (not in Pakistan) laminar black lines. Stamens in `3' fascicles (2+2+1). Ovary 3-locular, 2-3.5 mm long; styles c. 2 x longer than the ovary, free, divergent, incurved near apex. Capsule (4-)5-9 mm long, ovoid to pyramidal, each valve with dorsal vittae and lateral vescicles, Seeds 1.0-1.2 mm long, shortly apiculate, not carinate; testa reti¬culate-pitted.

Fl. Per.: June-September.

Type: Europe, probably Sweden, Herb. Linn. 934/94 (LINN!).

Distribution: Europe and N. Africa to W. China and N.W., India (Kumaun). Introduced into E. Asia, America. Australasia and S. Africa.

In wet or dryish, shaded or open grassy places often near streams. or sometimes a weed of cultivation, 1200-3000 m. H. perforatum is a very variable species which reproduces largely apomictically (pseudogamously); but it seems that only a small part of its range of variation is present in the Flora area. It is poisonous to livestock.