Radiate

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.

Radiate
Image Credit: Sarah Spaulding
The striae of this Cavinula species are slightly radiate.
Radiate2
Image Credit: Marina Potapova
The striae of Navicula angusta are radiate near the center of the valve, becoming convergent at the ends.