PETU′NIA (Neo-Lat., from Brazilian petun, tobacco). A genus of plants of the natural order Solanaceæ, natives of South America, and during the nineteenth century introduced into cultivation in other countries for their beautiful flowers. Although naturally perennials, they are generally cultivated as garden annuals. The slightly viscid foliage emits a peculiar, often disagreeable odor, especially in the evening or during stormy weather. The common garden petunias are mostly hybrids of Petunia nyetaginiflora and Petunia violaceæ, which themselves are not frequently cultivated. Petunia nyetaginiflora is a stout species with white flowers; Petunia violaceæ, a trailing plant with purplish violet blossoms. The number of varieties is very large and includes single and double flowered forms, plain or variegated, with innumerable variations in color from pure white to deep violet, through rose, purple, pink, and many other shades. The finest flowers are produced on deep rich soils in sunny situations. They are well adapted for beds and borders and are also grown as house and conservatory plants. Since seedlings do not come true to the parent plant, the choice varieties are propagated by cuttings. These are put in sandy soil with bottom heat in August, potted singly after they have rooted, wintered in the greenhouse, and set out in the open in late spring.