Abstract
Continued botanical studies in some of the plant diversity centres of Saudi Arabia have led to the discovery of two genera new to the flora of Saudi Arabia. Descriptions and distributions of these two taxa, namely, Parthenium hysterophorus L. (Asteraceae) and Operculina turpethum (L.) Silva Manso (Convolvulaceae) along with distribution map are presented. With the present additions, the total recorded vascular genera for the flora of Saudi Arabia now stands at 855 and the number of species at 2,290, showing an increase of approximately 2 % species during the past one decade.