It’s January 1st and the floor of the wood is covered with fresh new leaves, growing in dense patches. The first flowers are starting to open. Within a week, the air is scented with a sweet fragrance. This is the winter heliotrope, which is just as much at home in Nowhere as it is in its native North Africa.
The winter heliotrope was probably brought to Britain by Victorian gardeners.
We have a large Victorian estate called Tyntesfield down the road, so originally it could easily have come from there. The plant has a big secret: its flowers are just for show!
The winter heliotrope is unusual because it has separate male and female plants. As far as we know, the Victorian gardeners only imported male plants into Britain, because they liked the showy flowers and its rich scent. So, although the flowers make good pollen, there are no female flowers available to receive it. These plants cannot make seeds.
How do the plants reproduce, if they cannot make seeds?
What is its big secret?
Below the soil the plant has a special underground stem, called a rhizome. During the year the rhizome stores food ready for the wintertime. Then, early in the new year, it grows new leaves and flowers.
During the summer the rhizomes grow so large, that they eventually break off and become new plants. This is a different way of reproducing, called vegetative reproduction. The plants are all clones, they have the same genetic information, which means that they all flower at more or less the same time.
So good is the winter heliotrope at growing in this way, that the plant is seen by some gardeners as an uwanted pest. It seems to grow well in Nowhere Wood, where it grows undisturbed.
1. What do you think are the advantages of being able to reproduce vegetatively, without making seeds?
2. Are there any disadvantages to having plants that all have the same genetic information. Is variation needed for the survival of plants?