Forms of adaptation required to preserve the species vary. One of the simplest ways of guaranteeing survival is by the production of vast numbers of seeds, and flowers of the field are known to be particularly vigorous in this respect.

The related Ivy Speedwell (V hederifolia L.), on the other hand, is very short-lived, germinating in autumn or winter if mild, then waiting to flower and complete its life-cycle the following spring. It is not to be seen in summer. The third of the speedwells commonly found in fields is the Wall Speedwell (V arvensis L.), which may germinate in autumn, then flower and die in spring; or it may germinate in spring and then grow as an annual during the warm summer months.

As the Latin name persica indicates, the Field Speedwell comes from the Orient. It was grown as an exotic plant in the botanical gardens at Karlsruhe, becoming established in the vicinity as an escapee in 1805. It took only a few decades for it to spread throughout Europe and now, almost two centuries later, it is found growing in fields, fallow land, and gardens in most parts of the world. In poor weather, reproduction may be by self Pollination without the flowers opening. It is a common weed in damp soil, particularly in root crops.

Coltsfoot is a plant of two guises. Early in spring, sometimes as early as February, scaly stems bearing lovely bright yellow flowers emerge above the ground.

Ivy Speedwell has leaves which are heart- to kidney-shaped, with several lobes resembling the leaves of ivy, whereas Buxbaum’s Speedwell has ovate leaves with a slightly heart-shaped base and a finely-toothed margin.

In the case of many plants, survival in a given habitat is aided by their ability to reproduce by vegetative means. Some plants put out new roots as soon as one of their stems touches the ground. The weed Gallant Soldier, for example, unless it dries up, will take root even if it is pulled up and left lying on the ground. Creeping Buttercup on the roots; Earth-nut Pea and Celandine by way of small underground tubers produced on the swollen roots. Besides modification in .a particular habitat, other methods of adap- tation on the part of weed-plants include adjustments to the life-style of the cultivated plants in whose company they grow. So, for example, annuals with a short growth cycle may appear at any suitable time and may even produce several generations a year.