Inventory, diversity and therapeutic uses of medicinal plants in the Tiaret Mountains (western Algeria) 1 Laboratory of Ecology and Natural Ecosystem Management, University of Tlemcen, Algeria 2 Faculty Natura and Life sciences, University of Tiaret, Algeria 3 Faculty of Nature and Life and Earth Sciences and the Universes, University of Tlemcen, Algeria *Corresponding author, email: nouar.belkacem@hotmail.fr ABSTRACT This study is devoted to the floristic (systematic, biology, chorology) and therapeutic (treated uses and diseases) analysis of medicinal plants in the Tiaret Mountains (western Algeria). The floristic inventory allowed us to identify 108 medicinal plants belonging to 41 families, including the dominance of the Asteraceae, Lamiaceae, Fabaceae and Orchidaceae with (15.7%, 7.4%, 5.6%, 5.6%) respectively. Also we identified 3 endemic, 4 rare and 8 protected species. The biological spectrum of these species is characterized by a high presence of the Therophytes (38%) followed by the Phanerophytes (20.4%). In biogeographical terms, Mediterranean biogeographical species are the most represented and make up more than half of the medicinal flora (52.8%). These plants are mainly used in order of importance in the treatment of the digestive tract, cardiovascular and dermal diseases with percentages of 18.6%, 10.7%, 7.5%. INTRODUCTION Medicinal plants are still a source of medical care in developing countries (Rebbas & Bounar, 2014). A large majority (70–80%) of people in Africa consult traditional medicine practitioners (TPMs) for health care (Cunningham, 1993). Alge- ria is a typical example and one of the countries with a long medical tradition and a knowledge of medicinal plants (Baba-Aissa, 1991), some of these plants are used by residents living in the area and are marketed by herbalists (Benaissa et al., 2018). But according to (Rebbas et al., 2012), the use of conventional medicine has led to the neglect of these ancestral practices, which risk being forgot- ten. However, this country remains poorly explored, even though it encompasses considerable natural re- sources distributed in different ecosystems and has considerable floristic diversity (Miara et al., 2019). In this context, the aim of this study is to identify and enhance the medicinal plants of the Tiaret mountains by their floristic analysis and their uses in traditional medicine. MATERIAL AND METHODS Study area Our study area is an integral part of the Tiaret Mountains, western Algeria (Fig. 1), which are lo- cated in the north of the department (Wilaya) and embracing the city of Tiaret in the south, they are between 700 and over 1200 meters high. The bio- KEY WORDS Floristic analysis; Inventory; Medicinal plants; Therapeutic uses; Tiaret Mountains. Nouar Belgacem 1* , Hasnaoui Okkacha 1 , Maamar Benchohra 2 & Tir Elhadj 3 Biodiversity Journal, 2021,12 (1): 129–138 https://doi.org/10.31396/Biodiv.Jour.2021.12.1.129.138 Received 30.04.2020; accepted 15.10.2020; published online 15.02.2021