Wednesday, 3 August 2011

Sex in the city


Late summer in London, and there is sex everywhere. Of course I work in a botanic garden which prides itself of displaying the sex organs of plants.

The provocative parade continues. The latest to grab my attention is a Clerodendrum, to the left of Kew Palace in the picture taken between rain showers this morning.

It has shocked or shocking looking flowers. The petals are flung back, the stamens (with the dusty purple mass on their tips) extend rudely way beyond the flower and the style (waiting for pollen from the dusty purple mass) seems keen to be somewhere else and dips away from the sprawling stamens.


I’m going to keep watching these flowers because I gather that the stamens will soon curl up and the style will straighten, bringing the fertile female part of the flower into prime position ready for fertilisation. Effectively the flower will change from being brashly male to pertly female.

This is a simple way to avoid the flower fertilising itself, encouraging the mixing of genes from different plants creating variety and the ability to adapt to new situations.

Clerodendrum species, along with various other plants, are sometimes called bleeding-heart. Presumably because the leaves turn blood-red in autumn - and you can see a hint of this colour in some leaves already - or perhaps even a nod to the rosy outer layer (calyx) of the flowers.

The species I photographed this morning is, I think, Clerodendrum trichotomum, commonly called White Tree Jasmine. (It's possibly variety trichotomum. I have a similar looking plant in my home garden, but with smaller flowers and leaves, labelled Clerodendrum trichotomum var. fargesii.

I'm tentative about the identification because I still feel very much at sea with the UK garden flora. I struggled enough moving from Melbourne to Sydney, with all those subtropical additions, but here in a new country, in a new hemisphere, in a new climate…

I’m sure someone can check this for me, or perhaps I’ll find a specimen with a label in the botanic garden. After all, labelling plants is one of the defining traits of my business. You might have noticed above that even some of the plants in my own garden (within the botanic garden perimeter) have labels!


Anyway, let’s assume it is Clerodendrum trichotomum. Most clerodendrums are native to warm parts of the world, like Tropical Africa and southern Asia. This species is from China and thereabouts and is one of the more hardy species in the genus.

It’s also a plant grown for its blue berries as well as its showy flowers. So in November I should be able to enjoy (visually - the fruits are poisonous) the success of these sexual shenanigans.

4 comments:

Merricks said...

I have to say that it has always surprised me that all those Victorian ladies were permitted to draw such very obscene objects as flowers. They are so overtly sexy.

Tim Entwisle said...

Just to take everyone's mind off sex, I still don't have a positive identification of the variety/cultivar (I think I have the species right!). There is an interiguing cultivar named from Kew material I think, called ‘White Ibis’. It might be this one and should chase up the following reference: Townsend, R. & Atkins, S. (2004). Clerodendrum trichotomum 'White Ibis'. The Plantsman (n.s.) 3 (2): 114-116. It's on my list...
Tim

Tim Entwisle said...

Having now seed 'The Plantsman' publication (thanks Greg Redwood!) I have something to look out for. If the outer floral parts (the calyx) remain white in fruit it's 'White Ibis'. If they turn bright red, then it's one of the other varieties.

The 'White Ibis' variant was discovered by Ray Townsend and Sandy Atkins (from Kew), along with Kouske Homma and staff from Niigata University and Niigata Botanical Garden, during a 2003 trip to Sado-ga-Shima Island. It seems this island is the only place where the variant grows naturally.

As an aside, the bird after which the cultivar is named were no longer found on the island when Townsend and Atkins visited, but there were plans to reintroduce them.

Tim Entwisle said...

Finally the fruits have turned blue (it's mid-September) - although not many of them set fruit - and I can confirm the persistent flower parts (the calyx) turned deep red, not white. So sadly it's not 'White Ibis'.
Tim