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The potential of phytoremediation of oil-based drill cuttings (OBDCs) contaminated soil was assessed by measuring the level of petroleum hydrocarbons reduction. The contamination experiment was simulated in a randomized complete block design by factorial of 6 × 3 × 2 × 2 for grass species (Pennisitum purpureum, Panicum maximum, Andropogon gayanus, Heteropogon contortus, Axonopus compressus, and Chloris virgata), drill cuttings treatments (0%, 25%, and 50% OBDCs contamination), time (0 day of planting and 105 days of harvesting), and growth stage (young and mature). The parameters assessed were total petroleum hydrocarbons (TPHs) in soils, roots, and shoots; bioconcentration factor in roots and shoots; and translocation factor. The TPH reductions achieved in 25% treatment level were young A. compressus (58.01%), mature P. purpureum, young A. gayanus and C. virgata (44.24%), young P. purpureum (27.67%), mature A. compressus (25.29%), mature H. contortus (2.56%), mature P. maximum (4.01%), and unplanted soils (2.10%). Thus young A. compressus, A. gayanus, C. virgata, and mature P. purpureum are recommended for TPH reduction in 25% OBDCs contaminated soils. Young P. purpureum and mature A. compressus can be used to achieve 25% − 27% TPH reduction. Reduction of petroleum hydrocarbon in oil-based drill cuttings (OBDCs) contaminated soils using grass species without addition of fertilizers. Addition of Axonopus compressus and Chloris virgata as grass species with potential to reduce petroleum hydrocarbon in OBDCs contaminated soils. Growth stage of grass species is an important consideration for phytoremediation of OBDCs contaminated soil. Determination of phytoremediation mechanism in OBDCs contaminated soil. [ABSTRACT FROM AUTHOR]

We compared the anatomy of the flower stalk (male and female) anatomy, stem, petiole, tendrils and median vein shape of three representative members of Cucurbitaceae (Citrullus lanatus, Cucumeropsis mannii and Citrullus colocynthis). These materials (flower stalks of the male, female, midrib, petiole and the tendril) were fixed in FAA, wax embedded, sectioned, stained and photographed with Leitz Diaplan photomicroscope fitted with Leica WILD MPS 52 camera. The midrid and lamina anatomy of these species showed clear variations in the layers of mesophyll, number and arrangement of vascular bunbles which are of taxonomic significance and are reported for the first time. These anatomical features suggest taxonomic affinity amongst the species and enhance the delimitation of the species. It also strengthens the fact that the species maintained as separate species and confirm the fact that the anatomical characteristics of the stem, petiole, flower stalks, midrib and leaf lamina are an important line of evidence in classification of these species. [ABSTRACT FROM AUTHOR]

The pollination and breeding strategies of two Abrus species (A. precatorius L. and A. pulchellus Wall. ex Thw.) were comparatively investigated in Nigeria, West Africa. Observations were made on the phenology, floral morphology and architecture, breeding and pollination system, as well as flower-insect interactions. During 1999-2000, Abrus precatorius was observed to flower twice a year (April to June and September to November) while A. pulchellus flowered only once, from October to December. Flowers of A. precatorius never opened, which indicted obligate cleistogamy in this species. The study has produced evidence showing that the type of breeding strategy in A. pulchellus is of the facultative type. There was no evidence of agamospermy in the two species. Fourteen insects and an arachnid belonging to eleven families in six orders were observed visiting flowers of the two species. Among these visitors, Chrysops longicornis, Riptortus dentipes, Rhinocoris bicolor and Rhinocoris rapax were the most likely to aid cross-pollination and hence are legitimate visitors. Our study suggests that low outcrossing rate occurs in both species despite the predominant cleistogamous characteristics in the genus. Occurrence of low outcrossing is a kind of evolutionary homoeostasis in both species for perpetuating healthy offspring. [ABSTRACT FROM AUTHOR]

Flowering, breeding mechanisms, and pollination biology of Cucurbita moschata (Duch. ex Lam) Duch. ex Poir. varieties were studied. C. moschata carries male and female flowers on the same plant and is pollinated by thrips and bees with nectar and pollen as major rewards for the pollinators. Both flowers begin opening between 0330 and 0400 hours. The male flower opens for about 8 to 9 h and the female opens for 6 h 30 min to 7 h. There is, however, a period of overlap in the flower anthesis of both sexes, which coincides with the peak of pollen viability and pollinator activity. Pollen viability is about 90% in newly opened flowers but decreases to about 62% on closure and crashes to 8% after 1 day. Stigma receptivity, measured by pollen germination on the stigma, lasts from 1 day before anthesis to 2 days afterwards. There was no evidence of non-pseudogamous agamospermy. [ABSTRACT FROM AUTHOR]