Striae that lean away from the central nodule, with the sternum as the origin. Radiate, or divergent, striae may occur throughout the valve, only at the valve center, or only at the valve apices. In contrast, striae are convergent if they lean toward the central nodule, with the sternum as the origin.
Barber, H.G. and Hayworth, E.Y. (1981). Guide to the Morphology of the Diatom Frustule. Freshwater Biological Association, 112 pp.