Sunday, November 15, 2009

aka Tradescantia




Half way through the week I got a message from Mr Subjunctive, over at Plants are the Strangest People. Had I any idea, he asked, why in the past few days he had had literally hundreds of hits from Italy - all for people searching for the plant Tradescantia pallida (the purple-leaved plant in the photo above). Well no, quite honestly I hadn't - but after a bit of research I managed to track it down.

A couple of days previously, the most widely read Italian newsaper - Il Corriere della Sera - (and I imagine much of the rest of the Italian press too) had published an article quoting some US research. The researchers placed T. pallida at the top of a list of the five houseplants most effective at absorbing pollutants from the atmosphere. And clearly the whole of Italy had decided it was a must-have. I spent the rest of the week imagining the hordes which would be camping outside the garden centres all night, desperate to get hold of the last puny specimen.


Tradescantia is a plant which confused me for years. I knew it even in my pre-gardening years, because Dad had it growing in the garden. It had a little purple flower and leaves a bit like those of a daylily (not that I knew what those were then). But then I heard the name being given to a houseplant with green and white stripey leaves. Oh - so that was tradescantia. Perhaps Dad got it wrong.

Then I started gardening and bought myself some gardening books. There was my stripey plant - Zebrina pendula, common name : the inch plant. Problem resolved. Dad was right all along.


But wait a moment - look at the entry for Tradescantia. It describes a species called Tradescantia fluminensis, and there's a photo. But that's a plant I'd had on the balcony for a couple of years without knowing what it was. I'd ended up ripping it out because it made such a nuisance of itself, invading the whole container and crowding out the other plants. There it is in the photo below, still under control. It's the plant in the forefront just in front of my antirrhinums. So that's Tradescantia??? What else does the book say ? Common name - the inch plant.



At this point, boy was I confused. All I can say is that I'm glad I hadn't also come across Setcreasea pallida, which Mr Subjunctive pointed out. That's it in the top photo. And yes, I know what I said before ...

I'll cut a long story and several hours of research short. It's another case of what I talked about before in the post On the naming of plants (and yes, I know that post is starting to obsess me. I promise not to mention it for at least another month.) The taxonomists keep changing their minds.

They're now all seen as different species of the same genus - tradescantia. There are 71 species in the genus altogether, many of which look nothing like each other - though the flowers tend to give the game away. Here, from the top, the photos show tradescantia pallida, tradescantia ohiensis, tradescantia zebrina, and tradescantia fluminensis - I think.

I mean, I did the research yesterday. They've probably all changed their names again by now.

However, whatever you call it, it seems that T. pallida is a good thing to have around. But then so are the other four on the list - and all the other plants whose anti-pollution effect people have been talking about for years. What are they and what do they do? I'll save that for another post....


Acknowledgements
...

Huge thanks to the photographers who made the following two photos available under
Creative Commons License on www.flickr.com :

Tradescantia ohiensis by dmills

Tradescantia Zebrina by abbamouse

... and more.

If you want to know more about Tradescantia pallida and Tradescantia zebrina, click on the links to see posts at Plants are the Strangest People. I couldn't better them so I'm not going to try. Go see for yourself.