its protective powers, and even during the closing years of the last century country folk hung beads made of its roots round children's necks.[29] Yarrow is one of the aboriginal English plants, and from time immemorial it has been used in incantations and by witches. Country folk still regard it as one of our most valuable herbs, especially for rheumatism. Mugwort, which was held in repute throughout the Middle Ages for its efficacy against unseen powers of evil, is one of the nine sacred herbs in the alliterative lay in the _Lacnunga_, where it is described thus:-- "Eldest of worts Thou hast might for three And against thirty For venom availest For flying vile things, Mighty against loathed ones That through the land rove." Harleian MS. 585. [Illustration: (1) ARTEMISIA AND (2) BLACKBERRY, FROM A SAXON HERBAL (Sloane 1975, folio 37_a_)] With the notable exception of vervain, it is curious how little prominence is given in Saxon plant lore to the herbs which were held most sacred by the Druids, and yet it is scarcely credible that some of their wonderful lore should not have been assimilated. But in these manuscripts little or no importance attaches to mistletoe, holly, birch or ivy. There is no mention of mistletoe as a sacred herb.[30] We find some mention of selago, generally identified with _lycopodium selago_, of which Pliny tells us vaguely that it was "like savin." The gathering of it had to be accompanied in Druid days with mystic ceremonies. The Druid had his feet bare and was clad in white, and the plant could not be cut with iron, nor touched with the naked hand. So great were its powers that it was called "the gift of God." Nor is there any mention in Saxon plant lore of the use of _sorbus aucuparia_, which the Druids planted near their monolithic circles as protection against unseen powers of darkness. There is, however, one prescription which may date back to the Roman occupation of Britain. It runs thus: "Take nettles, and seethe them in oil, smear and rub all thy body therewith; the cold will depart away."[31] It has always been believed that one of the varieties of nettle (_Urtica pilulifera_) was introduced into England by the Roman soldiers, who brought the seed of it with them. According to the tradition, they were told that the cold in England was unendurable; so they brought these seeds in order to have a plentiful supply of nettles wherewith to rub their bodies and thereby keep themselves warm. Possibly this prescription dates back to that time.