A very recent article in the Journal of Ethnopharmacology by a team of Indian researchers has found that an extract of False Daisy (Eclipta Alba) promotes hair growth in mice, measured by an increase in the number of follicles and the activity of those follicles.
False Daisy has a long history of use in Ayurvedic medicine for many uses, being known throughout India as “Bhringraj”. A popular use is to restore the rate of growth, colour and body of hair. There is a popular formulation which is readily available in India called Amla Bhringraj Oil which also contains Indian Gooseberry and coconut or sesame oil, which when applied to the scalp is said to restore colour to greying hair, reduce the rate of hair falling and increase the rate of growth of new hair, improving the body and shine.
Eclipta alba is found widely throughout the world, most commonly in India, Brazil, China and Thailand. It has been used in Ayurvedic medicine as a powerful liver tonic and protecterant, in the treatment of skin diseases, petpic ulcers, chronic hyperacidity, eye infections, as a general tonic to keep the body fit and healthy, as a rejuvenative. A dye made from the plant is used to dye hair and also for tattooing. It has anti-inflammatory properties and a paste of the fresh plant can be applied to bites and stings to alleviate the pain. It is used for infants to expel intestinal worms. It has been used to reduce uterine bleeding and pain after childbirth. It has even been used in China on snake bites!
Links:
http://www.ayurvedic-medicines.com/herbs/bhringraj.html
http://jiva.tradeindia.com/Exporters_Suppliers/Exporter15580.233702/Ayurvedic-Bhringraj-Hair-Oil.html
http://en.wikipedia.org/wiki/Eclipta_alba
Datta K, Singh AT, Mukherjee A, Bhat B, Ramesh B, Burman AC Eclipta alba extract with potential for hair growth promoting activity 
Journal of Ethnopharmacology, In Press, Accepted Manuscript, Available online 28 May 2009 doi:10.1016/j.jep.2009.05.023
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T8D-4WD1C08-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=87e716fed6c71d9039816096b879ee69
