Seasonal changes of gipogeodiatropic shoots anatomical structure of long-rhizome-forming herbaceous plants
Anatomical structure of underground shoots of perennial rhizome-forming plants was studied. A cortex parenchyma occupied 50-90% of the rhizome total volume. The cortex and the central cylinder are separated by the endodermis. U-shaped wall thickenings in the endodermis of Majanthemum bifolium rhizomes were found. Well developed sclerenchyma in the rhizome of Mentha arvensis and Achillea millefolium was shown. It was reduced during the autumn period. The greatest seasonal changing in anatomical structure of Mentha arvensis rhizomes was found. It is connected with rapid growth, active branching and early plants particulation. The increase of the parenchyma cells size and the number of vascular bundles and reducing the diameter of xylem vessels was shown. As a whole, the anatomic structure of rhizomes depends on functional activity of underground shoots, strategy of life and ecologo-cenotic conditions of plants.