Abstract
The goal of this research was to investigate the species diversity and floristic analysis of the family Poaceae in Libya depending on the data provided from the Flora of Libya series. 3 species (Bromus unioloides (Willd.) H. B. K., Eriochloa fatmensis (Hochst. & Steud.) Clayton and Chloris gayana Kunth.) were added as a new record to the family Poaceae in Libya. Results revealed that the family Poaceae in Libya is composed of 229 species belonging to 92 genera. Simpson’s Diversity index showed that the Family Poaceae has high diversity. The largest genera in the Family Poaceae in the flora of Libya are Stipagrostis and Bromus, which include 13 species. There are (13 species) of Stipagrostis in Libya (26%) of 50 species in the world. The life forms and chorological spectra of plant species were determined. There are no trees and shrubs species in our data, this due to the difficulties for the species to grow in dry habitat. It appears that annual and perennial life forms are the preferable strategy in the temperate deserts of Libya. Therophytes showed the maximum number of species (62.2%), followed by Hemicryptophytes (19.65%), Geophytes (13.5%) and Therophytes - Hemicryptophytes (2.62%). The results obtained from the geographical distribution of the species showed that the highest percentage is (31.88%) for the Mediterranean region, followed by (14.85%) Mediterranean / Irano-Turanian regions. Distribution of species clearly shows that the majority of species of the family Poaceae are located within the Mediterranean region.