The most likely explanation seems to be that stroking makes leaf tissues tougher.

We have obtained similar osmotic potential results with leaf tissue (data not shown).

The leaf tissue is eaten away up to the upper epidermis.

This symptom is associated with the production of oospores in the leaf tissue.

The upper leaf tissue registers 'writing' giving it the common name autograph tree.

Some experiments have suggested that leaf tissues of living plants emit methane.

According to light intensity, regular brown to purple spots develop on the leaf tissue.

As the butterfly caterpillar ages, its hunger for leaf tissue continues to grow.

The leaf tissue that is cut off is killed, resulting in a brown spot.

They do that, by removing the leaf tissue from the plant.