Résumé:
The geographical position and climatic diversity of Algeria give it one of the most diverse and original floras in the Mediterranean basin. Knowledge of the floristic composition and the distribution of weed communities allows good management of the cereal plot.
Weeds, also called adventitious plants, are plants considered as bio-aggressors naturally present in an environment, which develop in cultivated fields or gardens. Also called messicoles when it comes to cereal fields, the latter are adapted to the same soils and the same climatic conditions as cultivated plants. The objective of this work is to define messicolous plants, and to carry out a comparative synthesis work between the works published in Algeria in different regions as follows; the north presented by the wilaya of Mostaganem, Bordj Bou Arreridj, Médéa and Batna. The southern region presented by existing stations in Ouargla Ghardaïa and El Meniaa.
The bibliographic research is conducted on the biology, families and species of messicolous plants. the result shows that Poaceae and Asteraceae are respectively the dominant families in the Algerian flora in the north as well as in the south.
The overall flora studied demonstrated the existence of 48 families with 305 species and 201 genera. The overall analysis shows that the Algerian north is richer than the South in terms of messicolous plants species as well as the class of dicotyledons are the most dominant in the total of the messicolous flora with a proportion of 85% against 15% mono-dicotyledons.
This diversity is only a reflection of the immense floristic heritage that Algeria has across its vast territory that must be well preserved.
