The shaft is sometimes articulated with vertical hollow grooves or 'fluting'.

Their umbilici are all the same, a simple vertical groove.

Septemius stood looking down at him, his face drawn into vertical grooves, like the wall of a gully.

Here, she was as vulnerable as on the cliff face, apparently held in a vertical groove.

"There is a vertical groove running up here."

In addition to these wrinkles, many faint, closely placed spiral and vertical grooves are present.

Through the horizontal and vertical grooves they were covered by large marble blocks.

She laughed, taking her eyes from the traffic; he was grinning, his mouth bracketed in deep vertical grooves.

There are vertical grooves at the bases of the cusps.

The depth and width of the vertical groove may vary greatly.