Heliotropium

Heliotropium /ˌhiːliəˈtroʊpiəm, -lioʊ-/ is a genus of flowering plants in the borage family, Boraginaceae. There are 250 to 300 species in this genus, which are commonly known as heliotropes (sg. /ˈhiːli.ətroʊp/).

Etymology

The name "heliotrope" derives from the old idea that the inflorescences of these plants turned their rows of flowers to the sun. Ἥλιος (helios) is Greek for "sun", τροπεῖν (tropein) means "to turn". The Middle English name "turnsole" has the same meaning.

Ecology and human use

Several heliotropes are popular garden plants, most notably garden heliotrope (H. arborescens). Some species are weeds and many are hepatotoxic if eaten in large quantities due to abundant pyrrolizidine alkaloids. There have been cases of canine death due to over-ingestion of this toxic plant. Some danainae butterflies, such as the queen, like to visit these plants, as pyrrolizidine alkaloids produce a pheromone to attract mates. Though it is not palatable and most animals will completely ignore it, there have been cases of horses, swine and cattle being poisoned due to contamination of hay.