The present study was conducted to evaluate the ecological characteristics and the bioactive metabolic products of C. procera. Also, the crude methanol extract of the aerial parts of calotropis was examined for antioxidant and antimicrobial potentialilties. The scrubland dominated by C. procera represented an advanced stage of desert vegetation and comprised 33 species related to 14 families. Tamarix nilotica, Alhagi graecorum, Launea mucronata, Trichodesma africanum and Hyoscyamus muticus were the common associates. The major life-forms were therophytes, geophytes and chamaephytes. The assemblage of this community belongs to eleven floristics categories with predominance of Sahara-Sindian, Sahara-Arabian and Sudano-Zambezian. The flavonoids and polyphenols contents of the aerial parts of C. procera were 0.185 and 0.37 g/100g, respectively. Thirteen fatty acids were detected among them undecanoic, palmitic, lauric, myristic and linoleic acids. The Calotropis methanolic extract exhibited free radical scavenging activity with IC50 value of 0.35 mg ml-1. It is showed antimicrobial spectrum only against Bacillus subtilis.

The present study provides quantitative assessment of the hydrosoil and overlying water characteristics in addition to vegetation analysis of five aquatic habitats and their wet shorelines dominated by Ceratophyllum demersum, Myriophyllum spicatum, Potamogton crispus, P. nodosus and P. pectinatus. Experimental study was conducted to evaluate rate of release of heavy metals from living and dead hydrophytes to the surrounding water. The bottom sediments and overlying water were different markedly in the five habitats. The sediments samples were sandy textured with predominance of fine sanarticles size=0.211-0.104 mm), whereas sites and clay fractions constitute small proportion. Organic carbon, total soluble salts, anions and cations were generally higher in summer months. The floristic components of the five communities comprised 51 species related to 27 families. Poaceae, Asteraceae, Cyeprceae, and Potomogetonaceae were the major families contributing 45% of the recorded species. Therophytes were the common life froms. Rate of heavy metals release from living plant samples was higher than that from the dead samples.

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