Bracken

Bracken is a large fern found in temperate and subtropical regions of both hemispheres, with triangular fronds that grow singly from an underground rhizome and die back in autumn. Wikipedia says the extreme lightness of its spores has given it a cosmopolitan range. Cunningham calls it masculine, with Mercury and air, and lists healing, rain magic and prophetic dreams. He says burning bracken outdoors brings rain, and the root placed under the pillow brings solutions to problems in dreams. Kynes adds earth, Gemini and Mercury, and says English and Irish lore held that fern spores gathered on Midsummer's Eve made a person invisible. She says that in Scotland witches were said to avoid the plant, and that its roots were used in love charms and divination. She has a small piece of dried frond burned to clear negative energy and banish unwanted spirits. Cunningham, Kynes and Wikipedia all record hazards, set out in the safety notes.