MORPHO-ANATOMICAL CHARACTERS OF THE INVASIVE SPECIE Iva xanthiifolia Nutt.

Iva xanthiifolia is an adventive species belong to the Asteraceae family, originated from North America. It is toxic specie, abundantly near the roads and rail ways in some Romanian areas like Dobrogea, Moldova and Transilvania and it can become a weed in the field crops. It is annual plant having 1 - 2,5 m height. The leaves are opposed in the lower part of the stem and alternated in the upper part, long-petiolate, ovate, double serrate, trinervate and scabrous. Morpho-anatomical analyses were made at the stems and leaves collected from the plants meet on the salt soil in the North-East of Dobrogea region, in the Plopul village of the Tulcea county. The transversal sections were made in the stem, petiole and lamina of leaves. The microscopic observations were made in both epidermis of the lamina leaf. The secretory canals were identified in the cortex of the stem. The vascular bundles from the stem and petiole are bicollateral. The non-glandular and secretory pluricellular hairs were observed in both epidermis of the leaves. The leaves are amphistomatic and the stomates were identified in upper and lower epidermis. The stomata are anomocytic type. The mesophyll of the leaf is bifacial. [ABSTRACT FROM AUTHOR]