Saturday, November 3, 2012

Tubular bells

The lavender broomrape is a rare parasitic plant that depends for its existence on pitch trefoil, the same plant on which the caterpillar of the goldwing, the moth which was featured in last week’s article, feeds.

It is one of twelve species of broomrape that have been recorded in the Maltese islands. In Maltese it is known as budebbus vjola.

Broomrapes do not have chlorophyll, the green chemical that is responsible for photosynthesis in most plants.

They cannot photosynthesise and depend on other plants to obtain nutrients. Different species of broomrape parasitize different species of plants. Some, like the lavender broomrape, parasitize one species of plant while others can live on different host species.

Some species are of importance because they parasitize agricultural products. The best known of these is the bean broomrape, known in Maltese as buddebus tal-ful, which obtains its nutrients from bean plants much to the detriment of farmers.  

About 200 species of broomrape have been identified. Most of them are native to the cooler parts of the Northern Hemisphere. The broomrape plant usually consists of a yellowish or pale-coloured stem that grows vertically out of the soil. 

They are relatively small species, the largest being between fifty and sixty centimetres high. In most species the flowers, which resemble those of the snapdragons, are yellow, white or blue. 

As they do not have chlorophyll the leaves are functionless and have become reduced to small triangular scales.  

The seeds are very small and can remain viable in the soil in many years as they do not germinate unless they come into contact with chemicals produced by the roots of the host plants. 

After germination the seedling grows towards the roots of the host plant and attaches itself to it. 

Once attached to the root they start absorbing water and nutrients and will continue doing so until one of them dies. 

This article was published in The Times on 30.05,2912 

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