Crocus

Crocus is a genus in the Iridaceae family that is widespread, found in Europe, North Africa and in Asia. There are many species; the number varies depending on which resource you follow. Subspecies have been elevated to species levels and new species described, but both are not accepted by all. The standard reference on the genus was Brian Mathew, The Crocus, written in 1982, 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 The Smaller Bulbs and The Random House Book of Bulbs. A classic Crocus reference book is A Handbook of Crocus & Colchicum for Gardeners, by E. A. Bowles. It was first published in 1924 and is now out of date taxonomically, but it's an entertaining read by a legendary Crocus-lover. In 2010 Jānis Rukšāns published a book on Crocuses: A Complete Guide to the Genus that includes descriptions of species and cultivation information.

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 can be found on the Scottish Rock Garden Club's website where you will find pdf files for individual species. The Alpine Garden Society's encyclopedia for Crocus has images of most taxa and basic information about all. John Lonsdale also has an extensive Crocus collection, and has posted photos at his Edgewood Gardens website. Smaller versions of a number of John's photos are reproduced in this wiki, with his permission. Another source is "The Country of Crocus" the 'blog' of İbrahim Sözen.

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 species 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 first three pictures here from Tony Goode 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. The fourth photo below is of a plant with Cucumber Mosaic Virus (CMV) and the last is a photo of Crocus speciosus which is infected with CMV and Iris Severe Mosaic Virus. Photos 4-5 from Janos Agoston.

In general Crocus plants have very short stems; the seed pods only become visible at the end of the growing season, long after the flowers have vanished, when the stems elongate. Sometimes the seed pods remain at or below ground level. Seeds may be of the sweet sticky type attractive to ants and thus growing best when sown at 2 or 3 cm depth after washing. Each year a new corm grows on top of the old one, which then dies, often extra corms are also produced. A common characteristic is a white stripe down the middle of the ensiform leaf. Crocus enthusiasts are known as 'croconuts'. Photographs by David Pilling show seed pods, seeds on a 10 mm grid, corm development, a leaf and shoots of Crocus chrysanthus 'Romance' (left and characteristically of Crocus chrysanthus tinted yellow) and Crocus ancyrensis in mid-December. See Crocus Compared for comparisons of species.

More 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-b - Spring Blooming crocus c-e - Spring Blooming crocus f-l - Spring Blooming crocus m-s - Spring Blooming crocus t-z

Crocus species
Crocus abantensis	Crocus adamii	Crocus adanensis	Crocus aerius	Crocus alatavicus
Crocus aleppicus	Crocus alexandrii	Crocus ancyrensis	Crocus angustifolius	Crocus antalyensioides
Crocus antalyensis	Crocus atticus	Crocus asumaniae	Crocus balansae	Crocus banaticus
Crocus baytopiorum	Crocus biflorus	Crocus boryi	Crocus cambessedesii	Crocus cancellatus
Crocus candidus	Crocus cartwrightianus	Crocus caspius	Crocus chrysanthus	Crocus corsicus
Crocus cvijicii	Crocus cyprius	Crocus dalmaticus	Crocus danfordiae	Crocus etruscus
Crocus flavus	Crocus fleischeri	Crocus gargaricus	Crocus gilanicus	Crocus goulimyi
Crocus graveolens	Crocus hadriaticus	Crocus hermoneus	Crocus heuffelianus	Crocus hyemalis
Crocus imperati	Crocus isauricus	Crocus × jessoppiae	Crocus kerndorffiorum	Crocus korolkowii
Crocus kosaninii	Crocus kotschyanus	Crocus laevigatus	Crocus leichtlinii	Crocus longiflorus
Crocus malyi	Crocus mathewii	Crocus medius	Crocus melantherus	Crocus michelsonii
Crocus minimus	Crocus moabiticus	Crocus nerimaniae	Crocus nevadensis	Crocus niveus
Crocus nudiflorus	Crocus ochroleucus	Crocus olivieri	Crocus oreocreticus	Crocus pallasii
Crocus paschei	Crocus pestalozzae	Crocus pulchellus	Crocus reticulatus	Crocus robertianus
Crocus rujanensis	Crocus sativus	Crocus serotinus	Crocus sieberi	Crocus sieheanus
Crocus speciosus	Crocus stridii	Crocus thomasii	Crocus tommasinianus	Crocus tournefortii
Crocus vallicola	Crocus veluchensis	Crocus veneris	Crocus vernus	Crocus versicolor
Crocus vitellinus	Crocus wattiorum	Crocus yakarianus	Crocus yalovensis

Crocus named varieties and hybrids
Crocus chrysanthus 'Advance'	Crocus speciosus 'Aino'	Crocus cartwrightianus 'Albus'	Crocus chrysanthus 'Ard Schenk'
Crocus speciosus 'Artabir'	Crocus tommasinianus 'Barr's Purple'	Crocus minimus 'Bavella'	Crocus chrysanthus 'Blue Pearl'
Crocus sieberi 'Bowles White'	Crocus angustifolius 'Bronze Form'	Crocus chrysanthus 'Cream Beauty'	C. heuffelianus 'Dark Eyes'
Crocus chrysanthus 'Dorothy'	Crocus banaticus 'First Snow'	Crocus vernus 'Flower Record'	Crocus laevigatus 'Fontenayi'
Crocus ancyrensis 'Golden Bunch'	Crocus chrysanthus 'Goldilocks'	Crocus vernus 'Grand Maitre'	Crocus sieberi 'Hubert Edelsten'
Crocus imperati 'Jager'	Crocus vernus 'Jeanne d'Arc'	Crocus korolkowii 'Lucky Number'	Crocus goulimyi 'Mani White'
Crocus vernus 'Pickwick'	Crocus serotinus 'Poseidon'	Crocus chrysanthus 'Prins Claus'	Crocus kotschyanus 'Reliant'
Crocus chrysanthus 'Romance'	Crocus tommasinianus 'Ruby Giant'	Crocus sieberi 'Tricolor'	Crocus tommasinianus 'Whitewell Purple'
Crocus tommasinianus 'Yalta'	Crocus × luteus 'Yellow Mammoth'	Crocus chrysanthus 'Zwanenberg Bronze'

Fall Blooming crocus a-h - Fall Blooming crocus i-o - Fall Blooming crocus p-z - Spring Blooming crocus a-b - Spring Blooming crocus c-e - Spring Blooming crocus f-l - Spring Blooming crocus m-s - Spring Blooming crocus t-z