Convergent

Striae that lean toward the central nodule, with the sternum as the origin. Convergent striae may occur throughout the valve, at the valve center, or at the valve apices. In contrast, striae are radiate, or divergent, when they lean away from the central nodule, with the sternum as the origin.

Convergent2
Image Credit: Sarah Spaulding
The striae at the ends of Pinnularia sp. are convergent.
Convergent
Image Credit: Marina Potapova
The striae at the ends of Navicula angusta are convergent, while the striae are radiate near the center of the valve.