Aerial parts of T. fontanesii were collected during June 2004, in full blossom, in the Province of Tlemcen in four locations: Sidi-snoussi, Remchi, Sebdou et Sebaa-chiouki and again, during June 2005, in the last location.

The yield of oil obtained from the aerial parts of Thymus fontanesii harvested in the Province of Tlemcen (Algeria), calculated on dry material basis,varied slightly from station to station: Sebaa-chiouki = 5.20%, Sebdou = 5.25%, Sidisnoussi = 5.32%, Remchi = 5.46%. The composition of the four samples was quite similar, carvacrol (66.7-69.5%) being by far the main component. Other constituents, present at appreciable contents, were p-cymene (6.1-9.1%), gamma-terpinene (6.0-9.6%), linalool (3.0-4.0%), alpha-pinene (2.5-3.0%), myrcene (1.2-1.5%), and alpha-terpinene (1.1-1.4%). Conversely, thymol accounted only for 0.6-0.7% of the composition. Moreover, a sample harvested at Sebaa-chiouki, in June 2005, produced on oil with the same composition (68.3% of carvacrol). Obviously, aerial parts of T. fontanesii from the province of Tlemcen produced an oil whose composition differed substantially from that of the oil obtained from the same species harvested in Setif province and Constantine area (Algeria), dominated by thymol (67.8% and 68.2%, respectively).