Two general types of root apical organization, known as open and closed, have been identified in flowering plants. Closed roots are defined by the presence of tiers of initials that each give rise to specific cell files; open roots lack a clear organization of initials. T-divisions are specialized formative divisions of the initials that create new cell files and play a role in the determination of cell identity. While several studies have been conducted to decipher the patterns of T-divisions in closed roots, it was not clear if such cell division patterns occurred in roots with open apical organization. Root tips from legumes are known to exhibit open apical organization. Trifolium repens (white clover) was chosen as a model for study. Plants were grown in sand, and the primary root tips were embedded. Cross sections and median longitudinal sections were analyzed. T-divisions that result in the formation of peripheral root cap cells and protoderm cells were observed in the root tip at germination and in one, two, and three week old roots. Relative positions of these T-divisions in the root tip through time are being compared, and the possible patterns of cell division will be reported.

Key words: root apical meristem, root development, root, T-division, Trifolium repens