Wednesday, December 30, 2009

The aiming of the shrew

There was a small news article in the Royal Horticultural Society's The Plantsman journal about a novel way in which a particular pitcher plant gains its nitrogen requirements. This got me thinking about 'carnivourous' plants.

Plants need nitrogen to live, thrive and survive. However, some environments are a little lacking in this nutrient - for example peat bogs and rock outcrops. So, what is a plant to do? They have to find an alternative source of nutrients.

In nutrient poor habitats in the UK, we have the beautiful but deadly sundews. In some areas of the Lake District, you can't move for these deadly (at least to tiny invertebrates) plants. But they are hardly the stuff of nightmares.
Incidentally, Charles Darwin experimented on sundews to find what type of foods caused the greatest reaction. He found that his urine (rich in nitrogen) caused the plant to react very rapidly. Presumably anyone else's urine would do just as well.

The Venus Fly Trap is a bit more active in its capturing of small insects but is still rather small. Not very Triffid-like.

It's the pitcher plants which have really taken to alternative sources of nitrogen-rich materials.


Most rely on insects as a source of nutrients. Some, however, have become rather more ambitious...


(brilliant use of the word 'flange' by David Attenborough).

The pitcher plant which inspired this post, however, wasn't aiming for insects, rodents or other such prey. No. This plant has taken a more prosaic route to improving its nutrition. Nepenthes lowii has evolved to act as a toilet to a shrew. Droppings are full of nutrients, and the pitcher design has evolved into a shape "manoeuvring the animal to sit astride the pitcher orifice". The droppings can then be broken down in the pitcher's liquid, to provide much needed nutrients for the plant.
Nature, isn't it beautiful?

9 comments:

Good Food Shopper said...

Fenn’s, Whixall & Bettisfield Mosses National Nature Reserve (near Whitchurch, Shropshire) is also a good place to see sundew, I recommend going on a guided walk as you can easily miss a lot of interesting flora and fauna.

Plant Mad Nige said...

Lovely to see sundews.
We have bladderwort in some of our local fen dykes - it catches small aquatic invertebrates, particularly water fleas, and has yellow snapdragon flowers in summer.
Also, around the shores of Killarney, one summer, I remember being impressed by large butterwort flowers (Pinguicula.) They were big, purple blue and from the distance looked like escaped streptocarpus. The leaves are sort of greasy, like butter, and curl in on themselves, to trap insects.
Not sure squatting shrews can be called beautiful, though!

patientgardener said...

It always amazes me how inventive nature is and how things adapt. Thanks for sharing this I found it really interesting

Mr. McGregor's Daughter said...

LOL, that is brilliant. I wish I could remember where I read about the killer Petunias, that kill tiny flies by entrapping them in the sticky "hairs," and then the flies fall to the ground and become fertilizer for the plant. Plants are just so amazing.

Tatyana@MySecretGarden said...

Wow! How interesting! Thank you educating me!

fairegarden said...

Can they breed one a little larger for humans? :-)

Esha Flora said...

it's nice post ..thank you for your information

seo reseller program said...

The Venus Fly Trap is scary!

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