Tuesday, March 29, 2011

Colours in the Maltese countryside

Every winter I notice that during this dark season the flowers are most wild flowers blooming at this time of the year are yellow. As the days get longer, the sun brighter and the air warmer other colours especially reds and pink start to appear more often. 

At the peak of the spring flowering season yellow ceases to be the dominant colour.

The most common flowers in winter are the cape sorrel (ħaxixa ngliża), and the crown daisy (lellux – which means bright yellow or shiny in Maltese). Another common species is the perennial hyoseris which is known in Maltese as żigland tal-pizzi. This might seem like a coincidence but in nature it is evolution that shapes life.

Flowers are the reproductive structures of plants. They consist of male and female sexual organs. The female organs are the ovaries which produce the ovules. The stamens are column-like structures. They are topped by an anther where pollen is produced. When pollen reaches the ovules fertilisation takes place and seeds are formed. Some flowers are fertilised by their own pollen but evolution has pushed plants towards cross-fertilisation as this ensures genetic diversity and makes plants better able to deal with changes in the environment. 

Pollen may be transferred by wind or in rare cases by water. Wind-pollinated flowers do not need to attract pollinators and they are usually small, unattractive structure with no fragrance. The pollen is small and light and contains little if any proteins and is thus of no nutritional value to animals. Other plants require animals, such as insects, birds or bats to transfer the pollen from one flower to another. 

These plants have showy flowers and attract animals by providing them with nectar and nutrient-rich pollen. They usually have large coloured petals and nectar guides which show pollinators were to look for nectar. These guides are sometimes visible only in UV light which we cannot see but which can be seen by bees. Flowers also attract pollinators by scent.

I have not yet seen any studies about the colour of flowers during different seasons but I think that yellow being a bright colour is easier to see in low light intensity. In winter brightly coloured flowers attract more insects as they are more easily seen in low light. In spring, having a yellow colour does not give them an advantage over plants with other colours. 

This article was published in The Times on 09.02.2011

Wednesday, March 9, 2011