crocus

Crocuses open when the temperature is exactly 23°C/73.4°F. When the temperature drops, they close. They are very accurate, reacting to temperature differences as slight as 0.5°C/1°F.

Wild crocuses growing in the Austrian Alps.

Sieber's crocus (Crocus sieberi). Native to the Balkans, Sieber's crocus is one of 75 species of crocus, low-growing perennials which generally flower in the early spring. Crocuses are native to the Alps, southern Europe, and the Mediterranean. Sieber's crocus is characterized by white to pale mauve flowers and a yellow throat.

Any of a group of plants belonging to the iris family, with single yellow, purple, or white flowers and narrow, pointed leaves. They are native to northern parts of the Old World, especially southern Europe and Asia Minor. (Genus Crocus, family Iridaceae.)

During the dry season of the year crocuses remain underground in the form of a corm (underground storage organ), and produce fresh shoots and flowers in spring or autumn. At the end of the season of growth new corms are produced. Several species are cultivated as garden plants, the familiar mauve, white, and orange forms being varieties of Crocus vernus, C. versicolor, and C. aureus. The saffron crocus C. sativus belongs to the same genus. The so-called autumn crocus or meadow saffron (Colchicum autumnale) is not a true crocus but belongs to the lily family.