HELIOTROPE or TURNSOLE, Heliotropium, i.e., a plant which follows the sun with its flowers or leaves, a genus of usually more or less hairy herbs or undershrubs of the family Boragi naceae, having alternate, rarely almost opposite leaves ; small white, lilac or blue flowers, in terminal or lateral one-sided simple or once or twice forked spikes, with a calyx of five deeply divided segments, a salver-shaped, 5-lobed corolla, and entire 4-celled ovary; fruit 2 to 4-sulcate or lobed, at length separable into four 1-seeded nutlets or into two hard 2-celled carpels. The genus contains 220 species indigenous in the temperate and warmer parts of both hemi spheres. A few species are natives of Europe, as H. europaeum, which is also a naturalized species in the southern parts of North America.
The common heliotrope of hothouses, H. peruvianum, popu larly known as "cherry-pie," is on account of the delicious odour of its flowers a great favourite with florists. It was introduced into Europe by the younger Jussieu, who sent seed of it from Peru to the royal garden at Paris. About the year 1757 it was grown in England by Philip Miller from seed obtained from St. Germains. H. corymbosum (also a native of Peru), which was grown in Hammersmith nurseries as early as 1812, has larger but less fragrant flowers than H. peruvianum. The species commonly grown in Russian gardens is H. suaveolens, which has white, highly fragrant flowers. What, from the perfume of its flowers, is some times called winter heliotrope, is the fragrant butterbur, or sweet scented coltsfoot, Petasites fragrans, a perennial plant of the family Compositae.