There was a Lecturer who claims to know botanical name of all plants,one day one of His students brought a leaf that He can never recognised.

Student ; Sir, can you tell us the botanical name of this leaf.

Lecturer ; (He looked @ it and asked) where Did you get this leaf ?

Student ;(replied and said,) by the road side Sir .

Lecturer ; why is it dusty ?

Student ; the dust on the road caused it Sir..

Lecturer ;(He looked down for a few seconds and said,) the botanical name of this leaf is called ''Road sider dusty vera.
From Gab. Hav a nice time.