Seedling Anatomy in Helianthus Annuus, Tagetus Erecta and Zinnia Elegans of Asteraceae

Primary tissue differentiation in two days old seedlings was studied in three species of family Asteraceae. In all the three species viz. , Helianthus annuus Tagetus erecta and Zinnia elegans, two protoxylem groups differentiate at alternate positions to two protophloem groups. The typical diarch root is established in all the three species. In all the three species the cotyledonary node is of trilacunar three trace type. In H. annuus the endodermis is double layered against protophloem elements and single layered type against protoxylem elements. The pericycle is single layered and parenchymatous type.