Crocus L.

Crocus is a popular genus in horticulture. Out of the ca. 80 species at least 35 are in cultivation in Europe (Mathew 1986). None is native in Belgium. Their determination is often problematic.

The degree of naturalization of species of the genus Crocus often is uncertain. In Belgium they are most often found in lawns in old estates and parks (as feudal plants) and were, in fact, formerly introduced deliberately. They are now more or less naturalized. In other habitats where Crocus-species are sometimes found (road verges, dumps) they often remain strictly ephemeral.

Only four taxa of Crocus have been reported in the wild in Belgium (see key below), although an enlarged knowledge of the genus could yield additional taxa.

1       Flowers predominantly yellowish (often striped purplish outside) === 2

         Flowers lilac, purple or white === 3

2       Bulb with covering splitting into rings (never fibrous). Anthers not sagittate, with more or less parallel sides === Crocus chrysanthus

         Bulb with fibrous covering. Anthers sagittate at base, wider at base than at apex === C. xstellaris

2       Leaves (1-)2-3(-4) mm wide. Flowers lilac-blue, purplish or reddish-purple with a white perianth-tube (ground-color of the perianth-lobes never white) === Crocus tommasinianus

         Leaves 4-8 mm wide. Flowers lilac, purple, violet or white, perianth-tube of the same color or darker than the perianth-lobes === C. vernus


Forster G. (1992) Crocuses. Wild Fl. Mag. 425: 30-32.

Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.

Kerndorff H., Pasche E. & Harpke D. (2016): The Genus Crocus (Liliiflorae, Iridaceae): A Descriptive Seed Morphology. Part one: Macroscopic Traits and Phylogenetic Relevance. Stapfia 105: 3-41.

Kerndorff H., Pasche E. & Harpke D. (2016): The Genus Crocus (Liliiflorae, Iridaceae): Taxonomical Problems and How to Determine a Species Nowadays? Stapfia 105: 42-50.

Lawrence G.H.M. (1954) Keys to cultivated plants 4. The spring-flowering Crocusses. Baileya 2: 126-137.

Londo G. (1998) Ervaringen betreffende de verwildering van krokussoorten: Crocus chrysanthus (Herb.) Herb. in Nederland ingeburgerd. Gorteria 24: 12-18.

Mathew B. (1977) Crocus sativus and its allies (Iridaceae). Pl. Syst. Evol. 128: 89-103.

Mathew B. (1982) The crocus. Batsford, London: 127 p.

Mathew B. (1986) Crocus. In: Walters S.M. & al. (eds.), The European Garden Flora, vol. 1. Cambridge University Press, Cambridge: 361-369.

Mathew B. & Brighton C.A. (1975) Studies in the genus Crocus. European Floristic and Taxonomic Studies: 76-81.

Maw G.A. (1886) Monograph of the genus Crocus: xx + 326 pp.

Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.

Van der Ploeg D.T.E. (1963) Kleinbloemige "wilde boeren crocussen" in Friesland. Gorteria 1: 145-147.

Warburg E.F. (1957) Crocuses. Endeavour 16: 209-216.

Wurzell B. (1992b) Spring flowering crocuses. BSBI News 60: 36-38.

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith