Grasses of Saudi Arabia: A Review

Abstract

Grasses are found in all Saudi Arabia habitats. Their success pertains to diverse growth habits, specific morpho-anatomical features and distinctive photosynthetic attributes. Their composite evolution involved Early-Cenozoic appearance in open-habitats, Mid-Cenozoic dominance in temperate regions and Late-Cenozoic spread into tropics. This process is reflected in composite grassland development with Paleogene appearance of open-habitat grasslands, Mid-Neogene expansion of temperate grasslands and Late-Neogene spread of tropical savannas. Holocene grass domestication involved genetic changes that induced traits pivotal for grass spread into new habitats. Palaeoanthropological evidence also revealed a crucial interplay between grass domestication and human agrarian history. Saudi Arabia diverse topography, vast latitudinal span, and steep altitudinal gradient encourage broad grass diversity distributed over saline saltmarshes, dry sand dunes, dry desert plains, arid desert pavements, cool highlands and cold mountains. This review briefly discusses grass origin, evolution, domestication and photosynthesis. It concisely describes geodiversity and climate of Saudi Arabia and presents comprehensive analysis of its grass origin, domestication, taxonomy, diversity, tolerance and photosynthesis. Grass distribution is also extensively discussed in relation to climatic gradients, edaphic properties, grass chorology and photosynthetic attributes crucial for species acclimation potential.