In this study, we investigated the comparative anatomy of 17 species from 14 genera of Asteraceae occurring in Nigeria. Dried materials obtained from University of Port Harcourt Herbarium (UPH) were used for this study. The midrib of specimens were hand sectioned, stained with 1% safranin or alcian blue, mounted on slide, observed under microscope and micro-photographed using Leica WILD MPS 52 microscope camera on Leitz Diaplan microscope. The results showed that twelve species Aspilia africana, Chromolaena odorata, Conyza sumatrensis, Emilia preatamissa, Eleutheranthera ruderalis, Metanthera scandens, Synedrella nodiflora, Tithonia diversifolia, Tridax procumbens, Vernonia cinarae, Vernonia biafrae and Emilia coccinea have secretory duct while Adenostemma sp., Ageratum conyzoides, Bidens pilosa, Eclipta alba and Vernonia amygdalina not have secretory ducts. The number of abaxial and adaxial parenchymatous cells, shape of the midrib, number and arrangement of the vascular bundle varied form one species or genera to other. These characters are dependable in delimitating the family.

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