This section is from the book "The Botanical Magazine; Or, Flower-Garden Displayed", by William Curtis. Also available from Amazon: The Botanical Magazine; or, Flower-Garden Displayed, Volume I.
Hypericum Balearicum. Warty St. John's-Wort.
Calyx 5-phyllus. Petala 5. Nectarium 0. Capsula.
HYPERICUM balearicum floribus pentagynis, caule fruticoso foliis ramisque cicatrizatis. Linn. Syst. Veget. p. 102.
MYRTO-CISTUS pennaei Clus. Hist. 1. p. 68.
Is according to Linnaeus a native of Majorca; Miller says that it grows naturally in the Island of Minorca, from whence the seeds were sent to England by Mr. Salvador, an Apothecary at Barcelona, in the year 1718.
The stalks of this species are usually of a bright red colour, and covered with little warts; the leaves are small with many depressions on their upper sides like scars; the flowers are not always solitary, but frequently form a kind of Corymbus.
It is a hardy green-house plant, and readily propagated by cuttings.
It flowers during most of the Summer.
Clusius informs us in his Hist. pl. rar. p. 68. that he received from Thomas Penny, a Physician of London, in the year 1580, a figure of this elegant plant, and who the next year shewed a dried specimen of the same in London, which had been gathered in the Island of Majorca, and named by him μυρτο κἱσον, or Myrtle-Cistus it appears therefore that this plant has long been known, if not cultivated in this country.
We may remark that Clusius's figure of this plant is not equally expressive with many of his others.
 The leaves being somewhat like those of the Myrtle, and a gummy substance exuding from the plant as in the Gum Cistus.