HYPERICUM, St JOHN'S WORT; a genus of the polyandria order, belonging to the polyadelphia clafs of plants.
Species. Of this genus there are 29 fpecies, moft of them hardy deciduous shrubs, and under-shrubby plants, adorned with oblong and oval fimple foliage, and pentapetalous yellow flowers in clufters. The moft remarkable are, 1. The hireinum, or finking St John's-wort. This rifes three or four feet high, with feveral shrubby two-edged ftalks from the root, branching by pairs oppofite at every joint; oblong, oval, clofe-fitting oppofite leaves; and, at the ends of all the young fhoots, clufters of yellow flowers. Of this there are three varieties; one with ftrong ftalks, fix or eight feet high, broad leaves, and large flowers; the other with ftrong ftalks, broad leaves, and without any difagreeable odour; the third hath variegated leaves. All thefe varieties are shrubby; and flower in June and July in fuch numerous clufters, that the shrubs appear covered with them; and produce abundance of feed in autumn. 2. The canarienfis hath shrubby ftalks, dividing and branching fix or feven feet high; oblong, clofe-fitting leaves by pairs; and, at the ends of the branches, clufters of yellow flowers appearing in June and July. 3. The afyron, or dwarf American St John's-wort, hath fpreading roots, fending up numerous, fender, fquare ftalks, a foot long; oval, fpear-shaped, clofe-fitting, fmooth leaves by pairs oppofite; and, at the ends of the ftalks, large yellow flowers. 4. The androfænum, commonly called tuffan, or park-leaves, hath an upright under-shrubby ftalk, two feet high, branching by pairs oppofite; and at the ends of the ftalks, clufters of fmall yellow flowers appearing in July and Auguft, and fucceeded by roundifh berry-like black capfulles. This grows naturally in many parts of Britain. 5. The balearicum, or wart-leaved St John's-wort, is a native of Majorca; and hath a shrubby ftalk, branching two feet high, with reddifh fcarified branches, fmall oval leaves warted underneath, and large yellow flowers appearing great part of the year. 6. The monogynum, or one-styled China hypericum, hath a shrubby purplifh ftalk, about two feet high; oblong, fmooth, fiff, clofe-fitting leaves, of a fhining green above, and white underneath; clufters of fmall yellow flowers, with coloured cups, and only one fyle, flowering the greateft part of the year. 7. The laftanthus, or Surinam St John's-wort, hath shrubby ftalks, branching a yard high; fpear-shaped ferrated leaves; hoary underneath, and yellow flowers from the axillas of the ftalks. It is a native of Surinam and Carolina.
Culture. The four firft fpecies are hardy, and will grow in any foil or fituation; the three laft muft be potted, in order to have fhelter in the green-houfe in winter. The two firft fpecies propagate very faft by fuckers, which are every year fent up plentifully from the
the root; and in autumn or spring may be readily slipped off from the old plants with roots to each, or the whole plant may be taken up and divided into as many parts as there are suckers and slips with roots, planting the strongest where they are to remain, and the weakest in nursery-rows, where they are to remain a year in order to acquire strength. They may also be propagated by seeds sown in autumn, in a bed of common earth, in drills an inch deep. The other two hardy sorts are also propagated by slipping the roots in autumn, or early in the spring; and may likewise be raised in great plenty from seeds. The three other species are propagated by layers and cuttings, planted in pots, and plunged in a hot-bed.
Properties. The tussan hath long held a place in the medicinal catalogues; but its uses are very much undetermined. The leaves given in substance are said to destroy worms. By distillation they yield an essential oil. The flowers tinge spirits and oils of a fine purple colour. Cows, goats, and sheep, eat the plant; horses and swine refuse it. The dried plant boiled in water with alum, dyes yarn of a yellow colour; and the Swedes give a fine purple tinge to their spirits with the flowers.