which element is incorrect

[snade17]

Hi dear experts. Could you tell which element of the sentence is incorrect:

1. Firstly, he spoke about the importance of the conference.

2. The rays of the sun touched the leafs of the trees and the grass.

[svartnik]

Hi dear experts. Could you tell which element of the sentence is incorrect:

1. Firstly, he spoke about the importance of the conference.

2. The rays of the sun touched the grass and the leaves of the trees and the grass.