Materia Medica is a Latin medical term for the body of collected knowledge about the therapeutic properties of any substance used for healing (i.e., medicines).
There are a number of must have Materia Medicas that any aspiring or practicing Homeopath should have on their bookshelf.
1. Materia Medica by William Boericke
2. Materia Medica of Homoeopathic Medicines by S. R. Phatak
3. Materia Medica of Homoeopathic Remedies: With New Remedies (Classics in Homoeopathy) by James Tyler Kent