Most of the plants called weeds look weedy. Generally they are unglamorous in appearance and have unattractive foliage.

The usual definition of a weed is, "a plant out of place," reflecting human bias. Actually pest plants are out of place only in terms of man's purposes.

In nature's scheme, they often serve useful functions, and judging by their success in wide-open competition with other plants, they are anything but out of place.

An important factor contributing to the widespread abundance of weeds is their ability to adapt to adverse circumstances. Horseweeds that sometimes grow 10-feet tall in favorable environments can also succeed in hard, dry soil, where plants only a few inches high may produce a crop of seeds.

Other weed species can thrive even in crevices of concrete. What a contrast to our pampered cultivated plants.

Another secret to the success of weeds is their effective method of reproduction.

Many of them bear tremendous quantities of seeds. Some species of pigweed commonly yield 100,000 or more seeds per plant.

Furthermore, some weeds have remarkable ways of assuring widespread dispersal of their seeds. The seeds either float in the breeze by means of tiny feathery parachutes, or they attach to clothing, fur or wool by hooks, burs or cleavers. Seeds of still others can remain dormant for many years until favorable conditions return.

In addition, some species can multiply by vegetative means as well as by seeds. purslane, common in gardens and lawns, not only produces many seeds but also can start new plants readily from broken off butts of stems that have dried for a week or two.

Bermuda grass root stocks that have been cut off and dried up can still regenerate. Chopping up a plant often simply multiplies it.

Ron Fodor is district manager of the Butler County Conservation District.