ABSTRACT:The physicochemical studies and phytochemical investigations of River Nun and the water hyacinth (Eichhornia crassipes) were carried out in relation to the distribution of Eichhornia crassipes (Mart) Solms, Family Pontederiaceae in the River Nun.. The physicochemical studies of the water showed that dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrate (NO 3 ), salinity and alkalinity (pH) had mean + SD values of 6.94 + 0.22, 5.86 + 0.42mg/L,13.76 + 5.76 mg/L, 0.237 + 0.082 mg/L, 7.25 + 0.37 mg/L and 5.92 + 0.32 mg/L respectively. Phosphate (PO 4 ) and sulphite (SO 3 ) were not detected. The pH and DO levels appeared to favour the growth of E. crassipes.The BOD values were relatively higher than those of the control. The phytochemical studies showed that E. crassipes contains flavonoids (luteolin, apigenin, tricin, chrysoeriol, kaempferol, azaeleatin, gossypetin and orientin), amino acids (methionine, valine, glutamic acid theonine, tryptophan, tyrosine, leucine and lysine), phosphorous, protein, organic matter and cyanide. Some of these phenolic compounds and cyanide contribute to the negative impact associated with the proliferation of E. crassipes, in aquatic systems in addition to blocking water ways. The high protein and total organic matter content of Eichhornia crassipes, however, make E. crassipes a potential raw material for the production of animal feed and organic fertilizers. The study also shows that this plant prefers an almost neutral pH aquatic environment with a substantial concentration of dissolved oxygen, an increased rate of biochemical oxygen demand with a substantial concentration of nitrates. These conditions explain why this plant thrives in freshwater habitats such as the River Nun. @JASEM

ABSTRACT:The antimicrobial capabilities of plant extract derived from the leaves of the cashew plant, Anacardium occidentale L. (Family Anacardiaceae), on two common human pathogens of clinical importance, Escherichia coli and Staphylococcus aureus were investigated. All test organisms were identified to be sensitive to the plant extract, although zones of inhibition were about 50% of those observed using the commercial antibiotic, ampicillin. In terms of sensitivity, S. aureus, a Gram +ve organism, without an outer membrane in its cell wall was more sensitive relative to E. coli, a Gram -ve organism, which possesses an outer membrane in its cell wall. The degree of sensitivity could probably be due to this outer membrane which when present prevents a substantial amount of the extract from making contact with the cell. The antimicrobial properties of A. occidentale are derived from the presence of a polyphenol, anacardic acid and other compounds, tatrols and tanins. Therefore, it is suggestive of the fact that extracts could be used as an antibiotic especially in poor communities. @ JASEM

Leaf epidermal morphology of four West African species of Khaya (Meliaceae) has been studied using both light and scanning electron microscopy. The cuticle may be striate, reticulate or verrucose. Epidermal cells are either isodiametric or irregular in shape. The anticlinical walls are of variable thickness and their positions are marked by raised ridges or shallow irregular grooves. Periclinal walls may be flat, concave or convex. Anomocytic stomata which are either superficial or slightly sunken occur in all taxa. Stomatal size and index are variable among all species. A dichotomous key for identifying the species, even if they are in a fragmentary condition, is presented.

Systematic evidence from seed morphology and palynology (number, position and character of the aperture) showed a lack of discrete discontinuities amongst the twenty species of Portulaca L. studied. Habit and general morphology, however, exhibited a dichotomy amongst these species which was supported by cytological (chromosome number), and phytochemical (leaf flavonoids) analyses. Consequently, the genus Portulaca is now delimited into two sections: Portulaca L. sect. Portulaca (Engelmann) Nyananyo and Portulaca L. sect. Rotundatae Poellnitz.

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