While daisies are pretty, they can frustrate gardeners as they grow almost as soon as mown down and appears even in the middle of winter. It gives its name to one of the most prolific and colorful floral families.
There are at least 20,000 species in the daisy family or Compositae, making it one of the largest families in flora. It is also one of the most conspicuous families and includes not only daisies but ragworts, groundsels, thistles, dandelions, coltsfoot, and a host of other similar plants.
If you want to know more about daisies, please read on.
Where Do Daisies Get Their Name?
The daisy, a contraction of day’s eye, is called because, in full sunshine, it opens wide, but as the light fades, the petals close. In dull weather, all you will see is a pink-tinged bud.
The flower heads of all members of the Compositae are made up of masses of small flowers, hence the family name. Ray flowers, bearing long white petals or rays, form the border of the daisy and yellow disc flowers, which do not have petals, make up the central portion. Each of these inner flowers produces pollen and fruits, while those around the margin only produce fruit.
The common daisy is probably the best-known composite. Under a magnifying glass, you can see that each daisy flower is not one but many separate flowers on a dome at the top of the stem. Each head has about 150 flowers of two quite different kinds. There are about 100 disc (yellow) flowers clustered in the center and about 50 spreading ray (white) flowers. Both kinds of flower bear seeds, but only the disc flowers produce pollen.
The daisy head resembles a single flower and functions like one too. It opens, attracts insects by offering pollen and nectar, becomes pollinated, and withers as its seeds ripen. This compound head of flowers, which functions as though it were one flower, characterizes the daisy family.
The daisy blooms from spring to late autumn, and even in mid-winter, you may see a few flowers on sunny days. Its ability to survive both winter rain and frosts and summer dryness and heat account for some of its success as a weed.
The daisy has all its leaves and buds at ground level, and its flower head grows on a leafless stem. As soon as the lawn mower chops off one daisy head, another bud is ready to shoot up and flower.
Dandelions are one of the most successful and conspicuous composites. Since their fruits, each containing a single seed, are widely dispersed on the wind, dandelions colonize recently cleared ground, and, once established, their deep, long-lived, and exceptionally tough roots help them to survive. Even a small piece of root left in the ground can regenerate a whole plant within a few weeks.
There are more than 100 types of dandelion, and they grow in various habitats ranging from wet marshes to dry chalky grasslands. Dandelions reproduce asexually. The seed embryos are not fertilized by insect pollination, as in many other flowers. Pollination is often required for the development of the seeds, and this happens when dandelions attract nectar-seeking insects.
Oxford ragwort originated from Sicily, where it grows high up on the lava-strewn slopes of Mount Etna. Trains would suck the seeds along the tracks, which provided them with a similar habitat to their native volcanic slopes. Oxford ragwort is a common weed in many industrial areas and has even given us new species, such as the Welsh ragwort.
The reproductive processes are complex. The pollen is usually sterile, and flowering occurs from March to June, when millions of yellow heads can be seen in the air.
Each seed is a replica of those of the parent plant, and they remain identical through many generations. A new type of dandelion only develops as a result of a mutation, a rare and accidental change in the genetic composition of a plant so that all its offspring are slightly different from their parents.
Coltsfoot is conspicuous as their bright yellow ray flowers spread in the sun. They look rather like small dandelions until you notice their pinkish stems. They appear in March before their broad leaves have grown.
Indeed, by the time the leaves develop, the flowers have been replaced by feathery seed heads dispersed by the wind.
The Welsh ragwort’s other parent was the groundsel. Hybrids between species are usually sterile and would be expected to die without leaving offspring.
This hybrid was fertile, and its descendants survived, different from both of their parents and unable to cross-breed with them. They are a newly formed species.
Groundsel is a common weed that scarcely stops blooming in sheltered sites, even in the middle of winter. Its flowering heads are not obvious or flower-like because they lack the cluster of bright yellow ray flowers you find in many species.
However, they produce thousands of seeds carried off by the wind. The plants also make excellent vegetables for pet birds and rabbits throughout winter.
Winter heliotrope is a particularly attractive member of the daisy family. Its strongly fragrant, lilac flower heads attract some insects in the milder days of January and February. This plant used to be confined to gardens, but it is now quite common in hedgerows and beside streams.