Ahmad bin Muhammad bin Mufarraj bin Ani al-Khalil, better known as Abu al-Abbas al-Nabati, Ibn al-Rumiya or al-Ashshab, (Arabic: أبو العباس النباتي‎, Abu’l-ʿAbbās al-Nabātī) (c. 1200) was an Andalusian scientist, botanist, pharmacist and theologian. He is noted for introducing the experimental scientific method in the area of materia medica. His techniques such as separating verified and unverified reports led to the development of the field of pharmacology. He was a teacher of fellow Andalusian botanist Ibn al-Baitar.