In mid-October as you explore gardens on campuses, local parks or even in your own back yard particularly in raised beds keep a look out for something special: a crocus blooming in the autumn! This striking purple flower is Crocus sativus L., or the saffron crocus, in the family Iridaceae, and is the source of the world’s most expensive spice.

Also known as the autumn crocus, this species has an ancient history stretching back to 2300 B.C. in Greece as the earliest records of the plant are from frescos painted on palace walls in Crete, Greece. However, just because it originated in Greece, does not mean it is native to the area. The saffron crocus is not wild, but rather a plant cultivated from Crocus cartwrightianus Herb., as the species name sativus (Latin for “cultivated”) indicates; this makes tracing the plant’s origins difficult. However, despite its apparent Greek origins and that it is also being cultivated in Iran and India, the geographic origin of its wild ancestor remains a bit of a mystery.

C. sativus is largely cultivated and grown for the production of the world’s most expensive spice, saffron. The vibrant red tendrils of this spice are actually the stigma and styles (the most external female reproductive structures) of the flower. Each bloom only produces three, long sets of stigmas and styles that dramatically drape themselves between the petals. Not only are the flowers themselves harvested by hand, but the will-be saffron strands must be separated from the flower by hand as well. As workers separate these delicate structures from individual flowers, their fingers are stained the characteristic warm yellow color by the release of α-crocin, the carotenoid pigment the responsible for both the color and aroma that make saffron so desirable as an herb in cooking. The high price-tag of saffron is mainly because of the manual harvesting and the fact that so many flowers must be harvested and processed for a minute amount of the spice; tens of thousands of flowers are required to produce just one pound of saffron.

The C. sativus plant, itself, is pretty special as well. While the plant produces perfect flowers, containing both male and female reproductive structures, it is sterile and can only be propagated through the division of bulb-like corms under the soil. The plant is also an antispasmodic, diuretic, aphrodisiac, stimulant, antidepressant, and anti-inflammatory. Besides the stigmas and styles being used for yellow dye, the beautiful purple petals can be used for a dye of an unlikely color: a bright teal. This species has also been used to make Roman perfume and has been used in Mesopotamian religious celebrations.

            There are a few concerns surrounding the growth of the plant and the economic side of the saffron spice. The underground corms of C. sativus are nutrient rich, making them the perfect food source for rodents that will dig up the corms and eat them, killing the plant. The saffron bulb mite, Rhizoglyphus robini, is also a common pest that poses some threat to the crop. Being underground, in a dark, moist environment, the corm is also susceptible to rot and fungal pathogens. However, the species itself has not been evaluated for its conservation status, indicating there is not much concern over the occurence of the plant. With regard to economics, as saffron has a high value as a spice, often times substitutes and false crops, like marigold and safflower, will be marketed as saffron with the hope that a cheaper product will pass for the true product, cutting production costs while matching retail success. Similar substitutions are made for other spices such as cinnamon and vanilla extract. When you shop for your saffron, make sure what you are buying is the real deal, or, better yet, pop some Crocus sativus L. corms in your garden and harvest home-grown saffron every autumn.

(Authors note: for those of you on the Muhlenberg College Campus, look for Crocus sativus in the raised beds in Parents Plaza in Mid-October)

References

Akbar S. 2020. Crocus sativus L. (Iridaceae). In: Handbook of 200 Medicinal Plants. Springer, Cham. https://doi-org.muhlenberg.idm.oclc.org/10.1007/978-3-030-16807-0_78

Crocus sativus – Plant Finder. Missouri Botanical Garden [accessed 2021 Feb 17]; http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=281106

Crocus sativus – L. c2010-2021. Plants For A Future. [accessed 2021 Feb 17]; https://pfaf.org/user/Plant.aspx?LatinName=Crocus+sativus

IUCN 2021. The IUCN Red List of Threatened Species. Version 2020-3. [accessed 2021 Feb 18]; https://www.iucnredlist.org/

Srivastava R, Ahmed H, Dixit RK, Dharamveer, Saraf SA. 2010. Crocus sativus L.: A comprehensive review. Pharmacogn Rev. 4(8):200-208. doi:10.4103/0973-7847.70919

Parker BL, Skinner M, Ghalehgolabbehbahani A. No Date. Saffron pest and diseases. [accessed 2021 Feb 18]. North American Center for Saffron Research and Development. https://www.uvm.edu/~saffron/Resources/Presentations/SaffronPests-ArashG.pdf