Crocuses are small perennial bulbous plants, widespread in nature in Europe, North Africa and Asia, especially in hilly or mountainous areas; there are about eighty species of crocus, of which about thirty are cultivated; there are evidences of the cultivation of crocus from Cretan and Roman paintings, therefore the crocus is among the ornamental plants that have been cultivated for the longest time in Europe. Of the various species grown in the garden, most of them bloom between the end of winter and the beginning of spring, but there is no shortage of autumn flowering species. In addition to the botanical species, various hybrids are obviously available, generally selected for their very lively color or the size of the flowers. The bulbs of crocus they are fairly small in size, and generally do not exceed 5-7 cm in diameter, with an oval shape, and are covered with a few layers of papyrus membranes, among which the outermost are divided into filaments. The flower in many cases appears before the leaves, and blooms directly from the bulb; a long tubular part, very thin, is divided at the top into six colored tepals; the crocuses they are yellow, white, purple, or even striped and variegated. The leaves are very thin, like blades of grass, slightly thick, shiny, covered with a protective cuticle; in the center the leaf is divided into two parts by a white groove, the upper page is dark green, the lower one is light; typically a single bulb produces one or two flowers and about 8-10 thin leaves.
Common crocus species: Crocus laevigatus
Crocus of Greek origins, widespread in the Aegean islands; the flowering of this crocus occurs in the autumn, but a hot and dry climate during the autumn can delay the flowering until December or January, and it is not uncommon for some bulbs to wait until late winter to produce their flowers. The dimensions are quite minute, the flowers are white, and bloom before the plant produces the leaves, therefore they seem to emerge directly from the bare earth. Very often the flowers have purple or darker streaks, which divide the tepals in the terminal part by about half. Very often the throat of the flower appears of an intense golden yellow color, which stands out on the rest of the white flower; stamens and pistils are also white. The "fontenayi" variety is perfumed, a fairly infrequent fact in crocus. The name laevigatus of this crocus derives from the fact that the bulbs are covered with shiny and compact membranes, which give a shiny and smooth appearance.