Muscari is a genus of perennial bulbous plants native to Eurasia that produce spikes of dense, most commonly blue, urn-shaped flowers resembling bunches of grapes in the spring. The common name for the genus is Grape Hyacinth (a name which is also used for the genera Leopoldia and Pseudomuscari). Another common name is Baby's Breath, although this is also used for other plants, particularly Gypsophila. A number of species of Muscari are used as ornamental garden plants.

The genus Muscari originated in the Old World, including the Mediterranean basin, central and southern Europe, northern Africa, western, central and south-western Asia. It has become naturalized elsewhere, including northern Europe and the United States.

Brian Mathew says that many species of Grape Hyacinths, including not only Muscari but also the related Leopoldia and Pseudomuscari, are difficult to distinguish. They usually have one or more narrow leaves which arise from a bulb. The flowers appear in the spring and form a spike or raceme, being held in a close or loose spiral around a central stalk. The flowers often become less tightly spaced as the flower matures. The flower colour varies from pale blue to a very dark blue, almost black in some cases (albino forms are also known). In some species the upper flowers may be of a different colour and shape to the lower flowers. Individual flowers are composed of six fused tepals forming a spherical to obovoid shape, constricted at the end to form a mouth around which the ends of the tepals show as small lobes or "teeth", which may be of a different colour to the rest of the tepal.