ABSTRACT
The genus Crocus, a member of the large family Iridaceae, comprises some 85 species having an Old World distribution, primarily in Mediterranean Europe and western Asia. The limits of the entire genus lie within the range longitude 10°W to 80°E, latitude 30°N to 50°N. Phytogeographically, the majority of species occur within the Mediterranean floristic region, extending eastwards into the Irano-Turanian region; both of these areas are characterized by cool to cold winters with autumn-winterspring precipitation and warm summers with very little rainfall; the latter region experiences much colder winters and generally less rainfall. The genus Crocus is well adapted to such conditions, the plants being in active growth from autumn to late spring and surviving the summer drought below ground by means of a compact corm. Many species commence their above-ground growth at the onset of autumn rains and flower almost immediately; some of these produce their leaves and flowers concurrently, or nearly so, while others bloom without leaves and delay their leaf production until the onset of warmer weather, usually in spring. These physiological characteristics, together with cytological information and morphological features of the corm tunics, bracts, bracteols, leaves, flowers and seed, have been used to divide the genus into a hierarchy of subgenera, sections and series (Mathew 1982), and to define the species within those infrageneric groupings. This classification is followed here and is repeated below.
