It's not a universal constituent of wild flower rich assemblages in the wild, nor is it totally necessary (think of the ease with which wild flowers can invade a lawn). But it does help a lot when you're trying to establish wild flowers on the relatively rich and fertile soil of a garden, and which you are not going to mow regularly. It's an annual, but once established it will seed itself each year. But it doesn't like shade.

3 sorts of wildflower grassland, roughly.

1) continuously grazed short grass - ie a lawn. If you don't fertilise, you will gradually get daisies, white clover, purple self-heal, blue veronica etc. Mow it slightly long, and leave un-mown for 3-4weeks in about July to get bloom and seeds.

2) pasture - grows in spring, grazed for rest of year. Plant with early things - wild daffs, primroses, cowslips, start cutting when leaves of bulbs have died down, and keep it about 3-4inches long fr the rest of the year.

3) meadow - graze ((mow) in early spring,, then leave to grow all summer, finally cut (for hay ;-) )when everything has flowered and produced seed. My shady clay meadow has yellow vetchling and birds foot trefoil, blue and purple vetches, red clover, red greater burnet, purple knapweed, blue field geranium,, and, just for fun, tall red melancholy thistles (which,, although a thistle, do not have prickles).

There's nothing at all to say you shouldn't grow a mixture of wildflowers in a flower bed. Showy ones include red and white campion, foxglove, field and wood geraniums, oxe-eye daisies,, corn cockle, scabious, yarrow, poppy. Some of these are perennial, some annual.

Wild flowers (indeed any flowers) tend to look a bit unkempt when you're letting them go to seed. If you keep any edges tidy - weed paths, keep adjacent grass well mown - the overall effect is still of a cared-for garden rather than a piece of wasteland.