This thesis explored phytosociology, ethnobotany and conservation status of the flora of Mohmand Agency (FATA, Pakistan). Flora from 10 selected sites comprising 170 plant species was distributed among 144 genera and 49 families. Among angiosperms, Asteraceae and Poaceae were the two leading families, with 22 species each, followed by Brassicaceae and Fabaceae with 11 species each. Moreover, Lamiaceae, Boraginaceae and Amaranthaceae were some of the other important families. Dicots were most dominant with 141 species from 118 genera and 43 families; monocots were 27 species from 24 genera and 4 families. Gymnosperms were very sparsely distributed in the area with a representation of only 2 species (Ephedra intermedia and Pinus roxburghii). It is worth mentioning that Astragalus was the most represented genus with 4 species. Vegetation of the area was classified in 40 different plant communities on the bases of altitude and seasonal variation. Based on diversity indices Artemisia-Brachypodium-Aristida and Aristida-Hordeum-Phalaris were the most diverse communities. Species Richness evaluation of the communities indicated that Artemisia-Brachypodium-Aristida and Dodonaea-Rumex-Acacia communities were having the highest species-richness-values (3.1 and 2.86 respectively). Maturity Indices of all the communities were calculated which showed that DodonaeaBrachypodium-Hordeum and Hordeum-Medicago-Peganum communities were the most mature communities in the research area with MI values of 51.7 and 50 respectively. All the communities were dissimilar as none of the two communities had a similarity index equal to or more than 65 percent. Life form classification of flora indicated that therophytes were dominant with 97 (57%) species followed by nanophanerophytes and hemicryptophytes (21=12.4% species each). Chamaephytes (17=10% species), geophytes (7=4% species), microphanerophytes (3=1.8% species), mesophanerophytes and megaphanerophytes (2=1.2% species each) were also reported from the area. Leaf size assessment of the flora revealed that it was dominated by nanophylls (74=43% species) and microphylls (47=27.6% species). Leptophylls (33=19.4% species), mesophylls (11=6.5 species) and aphyllous plants (4=2.4 species) were also found in the area. Only 1 species—Nannorrhops ritchiana (0.6%)—was found to be megaphyllous. Phenological behavior of the plants was studied round the year. It was observed that March-to-June time period of the year was characterized by rich flora and most of the species were in active stage of their life. April was characterized by high flowering spell, with 41% flora in flowering condition. Most of the species were in fruiting condition during the month of May. January was with most of the species (63%) in dormant/post reproductive phase of their life cycle. Spring season was characterized by the presence of 166 species, followed by summer (135 species) and winter (95 species) while autumn—with 54 species—was the least populated season of the year. People of the area have a high degree of dependency on the plant resources of this area. Most of the plant species were predominantly utilized as fuel (93%), fodder (40%) and medicine (39%). People use many plant species for as first aid in common ailments. Some species were also used as timber (5%) and for many other miscellaneous purposes. Elder folks were found to be more informative, in terms of ethnobotanical information, as compared to the youngsters. Different ethnobotanical indices (Relative Frequency Citation, Relative Importance and Use Value) were also calculated to have a clear picture about the usage and importance of specific plant species. Rangelands were analyzed for annual biomass productivity with the aim to encompass the rangeland productivity of the research area. Average biomass production was calculated and was found to be 19.6g/m2. Conservation status of the species was evaluated, using IUCN criteria, enumerating 13 species in endangered category, 32 in vulnerable, 82 in rare and 38 species in infrequent category. No species was reported in dominant category indicating poor floristic health of the area. Biotic and abiotic stresses are responsible for the present status of the flora. Grazing (which is directly related to the palatability of vegetation) and cutting are the two major biotic stresses in the area. Plant species were divided into 4 classes of palatability: highly palatable, moderately palatable, less palatable and non-palatable. Results revealed 68 (40%) species to be highly palatable, 39 (22%) moderately palatable, 25 (14%) less palatable and 38 (22%) species nonpalatable. Five plant species comprising Caralluma tuberculata, Fagonia indica, Sageretia thea, Monotheca buxifolia and Ziziphus mauritiana were screened for elemental and nutritional contents. C. tuberculata was with relatively high amount of NPK (Sodium, Phosphorus and Potassium) followed by S. thea and Z. mauritiana. Micronutrient study indicated that Zn and Co was found in highest concentration (57ppm and 2.5ppm respectively) in M. buxifolia. Fe, Pb and Cr concentrations were highest (514ppm, 1.2ppm and 9.3ppm respectively) in F. indica. Carbohydrates, proteins, fats, fibers and ash contents of the selected species were analyzed. S. thea and M. buxifolia were with highest concentrations (57% and 51% respectively) of carbohydrates. M. buxifolia and C. tuberculata were having 3.5 and 3.1% protein contents and 1.2 and 1.2 % fats contents respectively, making them the highest fats and proteins containing plants. S. thea and M. buxifolia were the plants with highest relative ash contents (11.7% and 11.6% respectively) followed by F. indica and C. tuberculata (9.8 and 9.5% respectively). The plants were found to have enough nutrients for the foraging animals and there is no need of external augmentation of nutrients. Soil samples were collected from 10 study sites and were screened for different physicochemical attributes. The results showed that, to a greater extent, the soil of the area is silt loam in texture with pH ranging from 7.4 to 8.4 mol/L i.e. slightly alkaline.