Lineola

An areola that is elongated in the apical direction. From Latin for little line. Plural form is lineolae.

Lineolae compose the striae of the genus Navicula sensu stricto, or the Lineolate section of Navicula. This type of stria is called a lineolate stria.

Lineolate
Image Credit: Marina Potapova
The striae of Navicula capitatoradiata are lineolate, as are the striae of all the true Navicula.
N Tripunctata Lineolate Areolae 1
Image Credit: Marina Potapova
Areolae are often aligned in rows to form striae. In the genus Navicula, the areolae are elongated in the apical direction forming lineolate striae. This image shows the lineolate striae of N. tripunctata in SEM.
Gsn24379 02 1
Image Credit: Marina Potapova
The lineolate striae of Navicula species are visible in the light microscope in some species, but difficult, or not possible, to discern in others. Here, the lineolate striae of Navicula germainii can be seen.