Don’t judge a fruit by its mesocarp!

The old saying goes ‘don’t judge a book by its cover’, but for anyone who’s studied a bit of botany the fruity twist will be appreciated. (Credit to Stephen Vander Wall)

The reason I criticise the judgement of outward appearances is because the two atypically pretty plants below are going to be the subjects of my attention this year and had someone cast them aside as unattractive I might not have such an interesting albeit ‘nerdy’ project to work on.

blog erica flowers

These two species are endemic to small areas in the Western Cape and are likely to have out-of-the-ordinary pollination systems as they are not attractive to the usual pollinators that we associate with Cape Fynbos.

Erica nabea and Erica occulta have not yet been studied and this leaves me with the urge to figure out what is pollinating them or if they are fertilising themselves.

E. nabea is found in the Outeniqua Mountains above George and Knysna and grows to about 1.5m in height. Its flowers are green and white and appear between May and August.

E. occulta is found exclusively on a small patch of limestone on the Southern Agulhas Plain near Pearly Beach. It flowers between August and October and its flowers are hidden in a mass of hairy leaves. It is extremely localised and its <6 km² distribution is threatened by the alien invasive, Acacia cyclops and the potential construction of a nuclear power plant.

Blog eric distribution

Unfortunately, removing the threat of the competing acacia and preventing the construction of a nuclear power plant may, in this case, be an easier feat than rescuing this species as its population is so small that it could be on the verge of extinction. The population consists of about 50 individuals and their genetic diversity and their subsequent ability to adapt to change may be very low.

As part of my Honours project I am going to look at the micro-satellites of these two species to assess the level of heterozygosity in their populations. The heterozygosity of the micro-satellites is a fancy way of saying that I am going to investigate the genetic variation of the plants in the population.

But, some species are adapted to being selfers (they fertilise their ovules with their own pollen). These species don’t need to invest in making colourful flowers or lots of nectar to attract pollinators. E. nabea is an Adelopetalum meaning unseen or secret and E. occulta is named from occultus meaning secret or hidden. Maybe these two species are adapted to selfing and hopefully by the end of my experimenting and observing I will be able to understand what these plants are doing so secretly. I also hope that they still have enough genetic diversity to see them through the imminent climate change as it will be sad to see such unique plants go extinct.



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s