Crocus is a genus in the Iridaceae family that is widespread, found in Europe, North Africa and in Asia. There are more than 80 species. The standard reference on the genus is Brian Mathew, "The Crocus" (London, Batsford; Portland, Timber Press, 1983), but at least half a dozen taxa, including new species, have been described since its publication. Other reference books that are helpful with this genus are Mathew, 1987, and Phillips and Rix, 1989, listed more completely in References. Crocus Species in the Garden was the topic of the week for the Pacific Bulb Society list in February 2003. This discussion was led by Tony Goode. Click on this link for his Introduction. His Crocus Pages web site has images of most taxa and some basic information about all.
Some species bloom in the fall, before, with, or after leaf dehiscence, some in the winter, and some in the spring. Seasonality is relative on these pages, which means the bloom time varies depends on where the grower lives. Those that bloom in the fall need a warm summer dormancy. Those that bloom in the spring need a cold dormancy. Those that bloom in the winter seem to bloom in winter of Mediterranean climate which is rather mild with little to no frost. Since frost is the limiting factor, the following pages are separated into fall blooming, and spring blooming for simplicity.
Crocus are susceptible to viral disease. This is usually visible in the flowers. This distortion may take the form of twisted petals, streaking (as in tulip fire), sometimes the flowers are depauperate and fail to open properly. The virus also reveals itself as light and dark blotching in the foliage which is most visible when the foliage first emerges. The pictures here have been manipulated to exaggerate the streaking in flower and foliage to make it more apparent. (Massive hike in contrast levels does this.) The third picture shows ones with distorted petals. The vectors are aphids which find refuge especially on the backs of the leaves. See the Virus page for more information. Photographs by Tony Goode.
Information and photos of species can be found by selecting the fall and spring blooming Crocus wiki pages listed below or by clicking on a specific species in the table below.
Fall Blooming Crocus A-H – Fall Blooming Crocus I-O – Fall Blooming Crocus P-Z – Spring Blooming Crocus A-I – Spring Blooming Crocus J-S – Spring Blooming Crocus T-Z
Fall Blooming Crocus A-H – Fall Blooming Crocus I-O – Fall Blooming Crocus P-Z – Spring Blooming Crocus A-I – Spring Blooming Crocus J-S – Spring Blooming Crocus T-Z