The Carnation Subclass (caryophyllidae) 10 Kinds Of Flower Development, Morphology,

The floral morphogenesis of 8 families in all 10 species from the Caryophyllidae was observed with a scanning electron microscope(SEM) in order to expand our knowledge of the morphogenesis and development of floral organs in the Caryophyllidae.Eight of them were report the first time.We discussed the origin of the pentamerous flowers of Nyctaginaceae and Caryophyllaceae.We also discussed the systematic signification of the common stamen-petal primordium in Caryophyllidae and Plumbaginaceae.The Polymorphism of Placenta in Caryophyllidae was canvassed together.The main results are summarized as fllows:1.Origin of the Pentamerous Stamens in NyctaginaceaeThe floral morphogenesis of Mirabilis jalapa shows that after the initiation of the five alternisepalous stamens,another one or two stamens will initiate additional.These one or two stamens were the degenerative trace of the eight stamens.When there only five stamens,the position will be disengaged.All in all,we sustain that the pentamerous stamens was derived from eight stamens in Nyctaginaceae.2.Origin of the Pentamerous Flowers in CaryophyllaceaeThe floral morphogenesis of Dianthus chinensis shows that the pentamerous sepals formed by the fusion of two trimerous organ whorls.The pentamerous stamens derived from the 1 lost from the two trimerous whorls.3.Common Stamen-Petal PrimordiumStellaria media and Limonium bicolor have common stamen-petal(CSP) primordium.We sustain that the petals developed from the CSP was not the real petals.4.Polymorphism of the PlacentaThe placentation of Chenopodium album,Achyranthes bidentata,Rheum palmatum, Rumex crispus and Limonium bicolor are all basal.The ovules of them are all initiated on the top of the flower apex directly.At the very beginning,the ovules are uncovered.In the forepart of ontogeny both Stellaria media and Portulaca oleracea have axiel placenta.At last,these axiel placentation will turn to the free center placentation.This type of free center placentation is a secondary phenomenon.We sustain that the free center placentation was derived from the axiel type.Zygocactus truncates has parietal placentation,and the ovules are only born on the middle part of the ovary,without the top and the basal part.5.Position of the Ovule Born Our results show that the ovules of Mirabilis jalapa,Chenopodium album,Achyranthes bidentata, Rheum palmatum,Rumex crispus and Limonium bicolor are all born on the top of the floral apex directly,they are the continue of the axile,not like that born on the foliar organ.