Milk thistle - Definition and Overview

Milk thistle
Silybum marianum
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Asterales Family: Asteraceae Genus: Silybum
Species
Silybum eburneum Silybum marianum Silybum × gonzaloi
Ref: IPNI Query (http://www.ipni.org/ipni/plantsearch?find_genus=silybum&find_isAPNIRecord=on&find_isIKRecord=on&query_type=by_query&back_page=query_ipni.html)

The milk thistles are the genus Silybum of flowering plants, in the daisy family (Asteraceae). They are native to the Mediterranean regions of Europe, North Africa, and the Middle East.

Members of this genus grow as annual or biennial plants. They have large, disc-shaped pink to purple flower heads. The leaves are toothed and thorny, as in other genera of thistles.

Only two species are currently classified in this genus, Silybum eburneum, known as the Silver Milk Thistle, the Elephant Thistle, or the Ivory Thistle, and Silybum marianum, the Blessed Milk Thistle, which has a large number of other common names. The two species hybridise naturally, and the hybrid is known as Silybum × gonzaloi. A number of other plants have been classified in this genus in the past but have since been relocated elsewhere in the light of further research.

By far the more widely known species is S. marianum which is known to give some remedy for liver diseases. It has been widely introduced outside its natural range, for example into North America, where it is classed as an invasive weed.

External links and references

• Milk thistle (http://www.nwcb.wa.gov/weed_info/milkthistle.html) - information at the site of Washington State Noxious Weed Control Board
• K. Flora, M. Hahn, H. Rosen and K. Benner. Milk Thistle (Silybum marianum) for the Therapy of Liver Disease. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9468229&dopt=Abstract) Am. J. Gastroenterology 93, 139-143.