A practical botanist will distinguish at the first glance the plant of the different quarters of the globe and yet will be at a loss to tell by what marks he detects them.

I demand of you, and of the whole world, that you show me a generic character... by which to distinguish between Man and Ape. I myself most assuredly know of none.

If a tree dies, plant another in its place.

Nature does not proceed by leaps.

We admit as many genera as there are different groups of natural species of which the fructification has the same structure.

When all the thoughts are concerning one thing and the person loses interest in other things, the melancholy begins.

The plant kingdom covers the entire earth, offering our senses great pleasure and the delights of summer.