The diversity of melliferous flora in Biskra, an arid region in South East Algeria, is revealed in the present study. Data were collected through visual inspection and information gathered from local guides at different prospective sites when we collected samples.A list of plant species valuable to honey bees was then established. The list consisted of 122 species distributed in 101 genera and 43 families, though the most represented were, in decreasing order, Asteraceae (22 species), Fabaceae (14 species), Apiaceae (8 species), Brassicaceae and Lamiaceae (7 species each), and Boraginaceae (4 species). These families alone account for a half (51.23%) of all taxa identified. However, Anacardiaceae, Resedaceae, Rosaceae and Solanaceae were represented by 3 species each. Amaranthaceae, Apocynaceae, Asphodelaceae, Cistaceae, Rutaceae, Tamaricaceae and Zygophyllaceae were represented by 2 species each. One species represented the rest of the families. Therophytes (30.33%) dominated the other biological types followed by Chamaephytes (28.69%), Phanerophytes (25.41%), Hemicryptophyes (10.66%) and Geophytes (4.92%). A flowering calendar as well as apicultural value of the most common melliferous plants is given. The melliferous flora included 37.70% nectariferous and polliniferous species at the same time, 31.15% polliniferous species, 27.86% nectariferous species, 1.64% as sources of propolis, and 0.82% as sources of resin.