St John’s wort
Vascular – Exotic
Herbs - Dicotyledons other than Composites
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
Terrestrial. Disturbed short tussockland, herbfield, bare land.
Hairless perennial herb to 1 m tall. Roots with slender, creeping rhizomes. Stems singly or severally from base, erect, round with 2 ridges, woody at base, upper branches in opposite pairs at 45 degrees. Leaves in opposite pairs, stalkless, narrow to oval, 10-27 x 1-8 mm, with many translucent glandular dots. Flowerhead a terminal, flat-topped panicle, dense, many-flowered. Flowers star-like, 8-20 mm diam, golden yellow, with 5 black-dotted petals, Dec-May. Stems usually die in autumn, leaving prostrate, barren, leafy shoots, often forming dense mats.
may be confused with many other closely related Hypericum spp, 5 adventive and 2 native. The native species lack black glandular dots, and are low to mat forming.
December, January, February, March, April, May
Eur, W Asia, N Afr
hypericum: From the Greek hyper (above) and eikon (picture), the plant was hung above pictures to ward off evil spirits
perforatum: From the Latin perforatus ‘pierced with holes’, depending on the species this may refer to the foliage covered in punctate oil glands
Reason For Introduction
Life Cycle Comments
Perennial. Relatively long-lived.
Reproduces from seed and rhizomes.
The numerous seeds are contained in capsules.
Seeds via wind (minor), possibly livestock. Rhizomes via soil and water movement.
Tolerates hot to cold temperatures, damp and drought, wind damage and is not grazed (poisonous).