Today is the birthday of Cornelius Herman ("Neil") Muller, the American botanist and ecologist.
Cornelius pioneered the study of allelopathy ("ah-la-LOP-OH-thee"). Allelopathy occurs when one plant species releases chemical compounds that affect another plant species.
Most gardeners know that black walnut is an example of allelopathy. In addition to the roots, black walnut trees store allelopathic chemicals in their buds, in the hulls of the walnuts, and their leaves.