Crocus sieberi (Sieber’s crocus)

Occurs throughout Greece and into southern Albania, Macedonia and southern Bulgaria, and possibly western Turkey.

Crocus sieberi grows from a corm (short underground swollen stem) and produces long, narrow leaves, usually with a pale stripe down their centre. The leaves can develop at or after flowering and surround the flowers, which are held above the ground by the tube of the perianth (sepals and petals).

The corm is surrounded by a tunic (coat) made up of the expanded bases of the true leaves and the papery sheathing leaves, called cataphylls, which surround the aerial shoot. The characteristics of the corm tunic are important for species identification.

In the early 1990s, Melvyn Jope found, in the eastern Peloponnese, a population of C. sieberi, some members of which were autumn-flowering. This is very unusual but nonetheless in line with several other typically spring-flowering plants of the eastern Mediterranean that have localised, autumn-blooming colonies.

Crocus sieberi subsp. sieberi growing wild in Crete (Image: Richard Wilford)

The Kew botanist and former Editor of Curtis’s Botanical Magazine, Brian Mathew, recognises four subspecies of C. sieberi. The Cretan plant is C. sieberi subsp. sieberi. It flowers as the snow melts and can be seen completely covering grazed areas in April. The flowers can reach up to 8 cm tall and are white with a yellow throat (where the petal tube widens) and purple staining on the outside of the outer perianth segments. This purple staining can vary from a narrow stripe down the centre of the segment, to an almost complete covering. The branched styles (female parts) are deep orange or yellow.

Crocus sieberi subsp. atticus comes from the Attica region of Greece. It has a more coarsely netted corm tunic than the others, and lilac-blue or violet flowers with a yellow throat.

Crocus sieberi subsp. sublimis occurs from the Peloponnese to southern Albania, Macedonia and southern Bulgaria. It has pale lilac flowers with a pale yellow throat. Some forms with a deeper flower colour and a zone of white between the two colours have been called C. sieberi subsp. sublimis forma tricolor.

Lastly, subsp. nivalis has lilac-blue flowers with a yellow throat, and occurs in the southern Peloponnese.

Crocus sieberi is cultivated as an ornamental.

Sieber’s crocus is also used for food. The corms are eaten raw in Greece by mountain shepherds. The flavour is said to resemble hazelnuts. In Turkey, the leaves are gathered in the wild and eaten as greens.

Crocus sieberi makes a fine plant for a sunny position in a rock garden, flowering in late winter or early spring. The exception is Crocus sieberi subsp. sieberi, which needs to be kept drier than the other subspecies in summer and is best grown in a cold frame.

Although introduced in the nineteenth century, subsp. sieberi is still quite rare in cultivation. By the 1940s, C. sieberi was widely grown in England but the plants usually offered in the trade had light mauve flowers. These must have been one of the other subspecies, all of which have flowers in various shades of lilac or violet.

Crocus sieberi can be seen in the in the Davies Alpine House and Rock Garden at Kew, and at Wakehurst.

Spirit-preserved, as well as pressed and dried specimens of Crocus sieberi are held in Kew’s Herbarium, where they are available to researchers, by appointment. The details, including images, of these can be seen on-line in the Herbarium Catalogue.

Search Kew’s science databases for more information on this species

Visit Kew’s Davies Alpine House

Visit Kew’s Rock Garden

Read the Alpine & Rock Garden Team blog

Buy 'Alpines from Mountain to Garden' by Richard Wilford

Curtis’s Botanical Magazine (Wiley-Blackwell)

Royal Horticultural Society – Crocus sieberi